Tag Archives: cockroach

Monogamous cockroaches practice minor cannibalism out of love

Adults of Salganea taiwanensis before (right) and after (left) mutual wing‐eating behavior. The right individual has long intact wings. The left individual has short wings. Most part of its wings has been eaten by its mate. Credit: Haruka Osaki.

The Taiwanese giant wood roach (Salganea taiwanensis) mates for life, spending the rest of its life inside rotten logs across Asia feeding and raising its young. A new study shows that this rare monogamous union is strengthened by minor acts of cannibalism, with the newlyweds taking turns munching each other’s wings down to stubs once they move into their new log together. According to researchers this consensual cannibalism has been facilitated and may have evolved thanks to the roaches’ monogamous bond.

This striking behavior has been identified for the first time in a new study published by Haruka Osaki from Kyushu University. The Japanese biologist first encountered wingless roaches six years ago while she was still a student. She noticed that their wings were chewed by something. Even then, she knew that it was highly unlikely that these marks were left by some predators, and rather were the result of the cockroaches eating each other’s wings. But why?

Years later, Osaki finally unraveled the mystery once she completed fieldwork for her Ph.D. She collected wild cockroaches from the forest and brought them to the lab, where she formed 24 couples. For three days, every move the roaches made was recorded by video cameras, including the moments when the insects started eating each other’s wings.

First, one of the bugs climbs on the other’s back and starts munching on the wings. When they’re ready to take a break, the bugs will swap positions before resuming. Sometimes, the roach having its wings eaten gives a violent shudder, which immediately causes the other to disengage and take a forced break before they’re ready to start again. Other than these rare moments, it didn’t seem like the roaches were in pain while they had their appendages eaten. Twelve of the couples partially ate each other’s wings, while the other twelve consumed the wings completely.

Cannibalism is rather frequent among insects and some spiders. Cannibals can benefit from a larger food supply following the elimination of competition, but also from the higher nutritional quality of feeding on arthropod body tissues rather than plant tissues. Some even cannibalize their mates, with the most notable example being praying mantises.

The Taiwanese roaches are radically different though. For them, cannibalism is a mutual thing, rather than only one mate being fed. Also, they don’t eat each others’ wings for nutritional value since there’s hardly any nutrients there.

The benefit lies in living more comfortably in tight quarters without having to deal with cumbersome wings. Since wings can also collect mold or mites, this minor cannibalism may also provide protection against diseases.

As for downsides, there don’t seem to be any since the roaches make a decision to mate for life, never again leaving their nest or seeking out other mates. You don’t need wings anymore if you don’t plan on flying again. Speaking to the New York Times, Osaki adds that in a natural world where the sexes typically have competing interests, the roaches are a rare example of mates that want the same thing.

The findings appeared in the journal Behavioural Notes.

Cockroaches may soon become unkillable due to pesticide immunity

Scientists have found that German cockroaches (Blattella germanica) are developing cross-resistance to different classes of insecticides. In other words, with each generation that survives the chemical onslaught, the roaches are becoming immume to the toxins that would have killed their ancestors. Soon enough, roaches may become nearly impossible to kill through chemical means.

A German cockroach feeds on insecticide. Credit: Purdue University.

It’s not just that the cockroaches are developing immunity to insecticide — what was shocking to witness was the rate at which cockroaches started developing this immunity. Sometimes, it was within a single generation.

“We didn’t have a clue that something like that could happen this fast,” said study co-author Michael Scharf, a professor and chair with the Department of Entomology at Purdue University in Indiana.

For their study, the researchers at Purdue tested the effectiveness of three different classes of insecticides sprayed onto roaches, which were let loose in apartment buildings in Danville, Illinois, and Indianapolis, Indiana, over a six-month period.

One group of roaches was sprayed with a single insecticide, a second population was exposed to two insecticide classes, and a third group was exposed to three insecticides in rotation (one per month for two-month cycles).

In order to track insecticide resistance across multiple generations, the researchers trapped live roaches in baby food jars and took them back to the lab.

The findings were concerning, with most roach populations either remaining stable or actually increasing. Surprisingly, the rotating pesticide trial was the most ineffective because it caused the most cross-resistance.

What happened was cockroach offspring would not only become resistant to a pesticide that their parents had encountered but also other classes of insecticides which hadn’t been encountered by previous generations.

The only successful experiment was the one that used a single pesticide. However, this occurred in a population of roaches that had almost no resistance to the toxin. In a subsequent experiment that introduced the pesticide to a population that had slightly higher resistance, the number of roaches actually increased — this time with a new generation of resistant survivors.

“If you have the ability to test the roaches first and pick an insecticide that has low resistance, that ups the odds,” Scharf said. “But even then, we had trouble controlling populations.”

The German cockroach is a remarkable survivor, beingly notoriously difficult to control. The problem lies in the fact that even a couple of individuals survive, they are quickly able to replenish the population and even return in stronger numbers. A single female can deliver up to 60 nymphs per birth and are even able to reproduce without males — what scientists term parthenogenetic reproduction or virgin births. Previously, a study found that it is equipped with large gene families responsible for the metabolization of toxic substances, including some chemicals found in insecticides.

The new findings reported in the journal Scientific Reports suggest insecticides will become increasingly ineffective at controlling roach populations. Instead, we’ll have to use a combination of alternative approaches, ranging from traps to improved sanitation.

“Some of these methods are more expensive than using only insecticides, but if those insecticides aren’t going to control or eliminate a population, you’re just throwing money away,” Scharf said. “Combining several methods will be the most effective way to eliminate cockroaches.”

German cockroach.

Bug bombs don’t kill the bugs, but they do expose you to pesticides

Bug bombs are really good — if you like having cockroaches for flatmates.

Orion insecticide.

Orion insecticide.
Image credits Tamorlan / Wikimedia.

New research from the North Carolina State University showed that total release foggers (commonly known as “bug bombs”) are ineffective at removing cockroaches from your home. The chemicals they release fail to reach the places that these insects tend to hang out in, such as the undersides of surfaces or inside cabinets.

Indiscriminate bombing

“There’s been a general assumption that bug bombs work to eliminate cockroaches indoors, but no one had conducted a formal assessment of their efficacy and any exposure risks,” said Zachary DeVries, an NC State postdoctoral researcher and the lead author of the study.

“We’ve done that simultaneously in this study.”

Besides not removing the majority of cockroaches, these devices also leave behind toxic residues — particularly in the center areas of floors and furniture. Cockroaches tend to avoid these areas, but they see heavy use by humans and pets.

The team tested four different commercially-available bug bombs that use various insecticide compounds in five apartment complexes. These complexes were chosen for their level of bug activity — all five had moderate to severe German cockroach (Blattella germanica) infestations. All the bombs used in the study contained pyrethroids, the team explains, a class of fast-acting insecticides. Some also contained other active substances, such as piperonyl butoxide, which prevents cockroaches’ bodies from metabolizing the insecticides.

German cockroach.

German cockroach, Blattella germanica.
Image credits Matt Bertone.

First, they estimated cockroach populations in 20 homes in these five complexes. Then, following the instructions on their labels to the letter, the team set up and set off the bombs. Cockroach populations were re-examined two weeks and one month after the bombs were used. Overall, these devices had no meaningful impact on the insects, the team finding no evidence of decline from their initial estimates.

“The bug-bomb products did absolutely nothing to control cockroach populations in these homes,” DeVries said.

The team also applied either commercially-available gel bait or a professional-grade gel bait in 10 additional homes. Gel bait is generally applied via a syringe to the areas where cockroaches hide. This bait was much more effective than the bug bombs both at the two- and four-week marks, the team notes, virtually eliminating cockroach populations in all of the 10 homes.

To help them better gauge the effectiveness of the bug bombs, the team placed roaches (some raised in the lab and others captured into the homes themselves) in cages on the floor and in upper cabinets of the homes involved in the study. The cages were greased so that the insects couldn’t escape. These cages were installed during the bug bomb testing phase of the study.

“The lab roaches, which are not hardy, had high mortality, as expected,” DeVries explains. “The roaches captured in the homes and then brought back, however, had far lower mortality rates than you would expect from direct exposure to bug bombs, confirming the ineffectiveness of these products when used for German cockroach control.”

Overall, then, the bug bombs had shown themselves ineffective in their intended role. With this in mind, the team set out to quantify their collateral effect — the risk of exposing people and pets to insecticides in their homes. The team swabbed floors, kitchen surfaces, walls, and cabinets in the homes prior to bug-bombing them. This preliminary analysis showed insecticide residue was already present in the homes used in the study, giving the team baseline concentrations to work with. These baseline levels can be explained by residents facing cockroach infestations — as was the case with the families involved in the study — using insecticides in an attempt to remove the pests. These residues were found in samples collected from the middle of floors and kitchen surfaces, DeVries explains, so the finding is “most disconcerting”.

The same areas were swabbed four to six hours after the bombs were deployed. The team reports that insecticide residue levels increased 600-fold on average across all horizontal surfaces. Swabbings performed one month after the study showed insecticide residue levels were still 34% higher than the baseline.

“Bug bombs are not killing cockroaches; they’re putting pesticides in places where the cockroaches aren’t; they’re not putting pesticides in places where cockroaches are and they’re increasing pesticide levels in the home,” DeVries said. “In a cost-benefit analysis, you’re getting all costs and no benefits.”

“This is of particular concern in low-income communities, where bug bombs are frequently used because professional pest control may be too expensive,” adds Coby Schal, Blanton J. Whitmire Distinguished Professor of Entomology at NC State and senior author of the paper.

Insecticides aren’t particularly healthy for you — by ‘particularly’ I mean ‘at all’. Pyrethroids, the same compounds used in this study, are preferred for household use due to their fast biodegradation/breakdown and relative low mammalian toxicity (except for cats) compared to other insecticides.  However, there is evidence that even pyrethroids have an adverse effect on the development of rats, causing behavioral changes that resemble Attention Deficit/Hyperactivity Disorders (ADHD) in humans. There have also been reported cases of anaphylactic shock after exposure to pyrethrum, although no link between pyrethroids and allergic reactions has so far been established in the scientific literature.

The paper “Exposure risks and ineffectiveness of total release foggers (TRFs) used for cockroach control in residential settings” has been published in the journal BMC Public Health.

Cockroach uses karate kick escape zombie-making wasps

Few things are more horrific than zombification — for humans and cockroaches alike. To escape this grisly fate, the American cockroach has developed a kicking technique worthy of a karate master.

Zombifying wasps

The emerald jewel wasp truly deserves its name — its bright-green color shining as it swiftly moves about. But what really makes it special is its hunting and reproducing strategy. Ever since the 1940s, scientists have noted the wasp’s unusual reproductive strategy, which involves “zombifying” a cockroach and injecting it with larvae. Essentially, the infected cockroach starts grooming extensively, loses its survival instinct and normal responses, and becomes an unwilling host and breakfast for the wasp’s offspring. The whole process is gruesome.

It wasn’t until 2003, however, that another study using radioactive labels showed that the wasp stings precisely into specific ganglia of the roach, mildly and reversibly paralyzing it. This temporary paralysis allows the wasp to inject a secondary dose in the victim’s head, eliminating its escape reflex.

Then, the wasp chews on half of the cockroach’s antennas and — since it is too small to carry it — leads him on to the burrow using the remainder of antennas like a leash. Eventually, the wasp lays a white egg inside the roach, and then leaves, after it fills the burrow with pebbles. The offspring wasp will eat the cockroach’s organs in a way that makes the insect stay alive longer, which increases the survival chances of the offspring. After only one mating session, wasps can successfully parasitize several dozen roaches.

But the cockroach isn’t exactly helpless.

Karate cockroach

“The cockroach has a suite of behaviors that it can deploy to fend off the zombie-makers, and this starts out with what I call the ‘en garde’ position, like in fencing,” said Ken Catania, a Professor of Biological Sciences at Vanderbilt. “That allows the roach to move its antenna toward the wasp so it can track an approaching attack and aim kicks at the head and body of the wasp, and that’s one of the most efficient deterrents. It’s reminiscent of what a movie character would do when a zombie is coming after them.

A frame-by-frame capture of the American cockroach defending itself against the emerald jewel wasp. Image credits: Catania Lab.

Catania studies predator-prey interactions, and he heard about this unusual relationship. He was surprised to see that no one had taken a closer look at how cockroaches try to defend themselves from wasps, so he used ultra-slow-speed video to capture roaches using the mechanism time and again to prove and understand it.

Essentially, before the wasp can get into position and deliver the first sting, the cockroach delivers a swift blow with its spiny back leg. It doesn’t always work, but 63% of adults managed to stay safe this way — which still means that 37% were slain. For juveniles, it was even worse: almost all of them failed in their attempt.

The study was published in Brain, Behavior and Evolution.

The Pacific beetle cockroach. Credit: Yasu Ueda/Flickr.

Cockroach milk might become the next superfood on millenials’ wish list

Move over almond milk and avocado, there’s a new superfood in town: cockroach milk. Wait a second — don’t roll your eyes just yet, because this is actually a serious possibility which researchers and some companies are investigating. Apparently, cockroach ‘milk’, or rather the liquid postnatal secretion of a certain cockroach species, is one of the most nutritious substances that we know of. Pound for pound, cockroach milk reportedly contains three times the energy of an equivalent mass of dairy milk.

The Pacific beetle cockroach. Credit: Yasu Ueda/Flickr.

The Pacific beetle cockroach. Credit: Yasu Ueda/Flickr.

The first hints that cockroach milk is worth our attention came in 2016, when an international team of researchers reported the first study of protein crystals sourced from the Pacific beetle cockroach (Diploptera punctata). This is a unique cockroach, in the sense that its the only viviparous roach that scientists know of. Like humans, the young are directly nourished inside the womb by the mother before they are born. So, while its relatives lay eggs, the Pacific beetle cockroach gives birth to live young.

Of course, that doesn’t mean that this cockroach has nipples. That would be odd. Instead, the milk is obtained by opening an embryonic beetle roach, whose guts will spill out nutrient-rich milk crystals that shimmer like glitter.

Diploptera punctata is the only known viviparous cockroach, an evolutionarily advanced condition in which the eggs have little yolk, but the developing offspring are nourished directly by the mother from the brood sac wall. Viviparity enhances larval development, because the time to reproductive maturity is substantially reduced in D. punctata relative to ovoviviparous species,” wrote the researchers in their study.

Nevertheless, the liquid secretion, which we’ll just call milk for the sake of simplification, is super nutritious, being rich in proteins, fats, and sugars. An analysis of the protein sequences showed that they have all the essential amino acids.

Since the study was first published, some people have taken note and are currently experimenting with ways to turn cockroach milk into food for human consumption. Gourmet Grub, a South African ice cream company, is one of the important companies giving cockroach milk serious consideration. Their solution is called “entomilk”, which is sourced from sustainably farmed insects. Gourmet Grub claims that it may be possible to harvest entomilk in a far more environmentally friendly manner than the traditional farming of dairy cows.

There are a couple of hurdles before this can happen. Firstly, scientists need to prove that cockroach milk is safe for human consumption, something which studies in the future will address. Secondly, milking cockroaches is tough work. Ten cockroaches produce only half a milliliter of product, and the harvesting process itself isn’t easy. As such, this might end up being a pretty expensive product, although even a sprinkle of cockroach milk in protein drinks could still be good. Some researchers are currently experimenting with genetically modified yeast — which is far easier to grow and harvest — to produce the same milk as beetle roaches.

But at the end of the day, the biggest obstacle in the face of widespread cockroach milk adoption is convincing people that it’s not a gross thing (provided scientists prove it’s safe). The taste itself isn’t anything special, confided Subramanian Ramaswamy, one of the researchers, to the Washington Post

So, any takers? Anyone?


Cockroaches might inspire the future of robotics


Credit: Will Kirk/JHU.

Cockroaches are some of the most resilient creatures in the world. Not only they’re incredibly stubborn pests, cockroaches are masters of escape being capable of quickly hiding in cracks and tiny crevices. They can even survive nuclear warfare, with a cockroach being able to survive 15,000 times the lethal radiation dose for humans. But while cockroaches are generally undesirable, that doesn’t mean we can’t learn from them.

In two related papers (1 and 2), Johns Hopkins researchers studied cockroach locomotion then mimicked it for palm-sized robots. The hope is to one day employ cockroach locomotion in robots that can be deployed in all sorts of rough terrain like a disaster relief site or even an unforgiving alien world.

The team led by Sean Gart, a postdoctoral fellow at Johns Hopkins, first closely followed cockroaches that scurried along tracks laden with two types of obstacles: large bumps or equally large gaps. These obstacles are supposed to mimic the kind of terrain the insects usually encounter.

When a cockroach has to make a run for it, self-preservation is of no consequence. Often, you’ll see cockroaches slam into a wall, only to continue their hastened escape on a different plane, up the walls.

High-speed cameras that filmed cockroaches on the tracks made by the researchers captured such moments. Gart and colleagues note that the cockroach’s head acts like a bumper, dampening the impact and allowing the insect to make a full flip in under 75 microseconds.

“Where they live, you have all sorts of stuff around you, like dense vegetation or fallen leaves or branches or roots,” said Chen Li, an assistant professor of mechanical engineering and senior author of the paper published in Bioinspiration & Biomimetics. “Wherever they go, they run into these obstacles. “We’re trying to understand the principles of how they go through such a complex terrain, and we hope to then transfer those principles to advanced robots.”

The Johns Hopkins researchers applied the lessons they learned about the cockroach’s exoskeleton and passive body shape by designing a multi-legged robot. The contrapton replicates the insect’s locomotion by employing the same underlying physics principles. The researchers even added a “tail” which helps balance the robot’s position similarly to how real roaches navigate large bumps and gaps on the tracks. Thanks to this seemingly unimportant addition, the robot could then traverse gaps and bumps that were 50% and 75%, respectively, larger than before.

To manage all those rough transitions, the researchers also fitted the robot with a cardboard ‘nose’ that mimics the roach’s squishy head.

A head-banging roach-inspired robot. Credit: JAYARAM ET AL.

A head-banging roach-inspired robot. Credit: JAYARAM ET AL.

“We are just beginning to understand how these critters move through a cluttered 3-D terrain where you have obstacles that are larger than or comparable to the animal or robot’s size,” Li said.

Li hopes that his research will lead to a new a class of roach-inspired robots that might one day explore Mars or distant moons. Perhaps, similar robots might also save lives in disaster relief sites following an earthquake or some other calamity, making their way through cracks and rough terrain to find survivors.

This research could genuinely cause a paradigm shift in how scientists design some types of robots, moving away from sensor-based controls in favor of pure body mechanics. In any event, for Li at least, cockroaches have now become a lot more interesting.

“I knew I would be working with these animals, and I was a little scared at first because they just run so fast, and they were so creepy,” Li recalls. “But as soon as I started working in the lab, I learned that it’s actually very easy to work with them, and they’re actually a very nice, fantastic model organism. Not just because they’re so robust and move so fast, but also because they’re very easy to handle and motivate to run and very”

[NOW READ] Cockroaches have different personalities and characters

cyborg cockroach

Cyborg cockroaches might save human lives someday

Half cockroach, half machine, these peculiar insects were hijacked by researchers at Texas A&M University for science. Electrodes implanted in their tiny brains send electrical signals that stir the roaches left, right or makes them halt. Effectively, the researchers are controlling their bodies. This may sound despicable – it actually is in many ways – but the benefits to humanity are far reaching. The cyborgs would be our eyes and ears in places otherwise inaccessible, like disasters sites in the wake of earthquakes or other environmental calamities. Picking the cockroach brain might also help us learn more about how our own brain works. This in turn could spur the development of brain-computer interfaces or a new generation of prostheses that faithfully mimic real limbs.

cyborg cockroach

Image: Courtesy of Texas A&M Engineering

Cockroach mind control isn’t exactly a new thing. Since the 1990s, scientists have been working with Frankenstein-esque roaches, planting electrodes in their antennae and sending electrical shocks to coerce the insects in moving in a certain direction.  At Texas A&M, researchers planted the electrodes inside the ganglion itself – a cluster of neurons that control the movement of the roach’s legs. According to Professor Hong Liang, right now the cyborg roaches obey commands 60% of the time. In fact, it depends on how distracted the cockroach is. If there’s a lot of sensory input, it will tend not to obey commands. Liang says with confidence, however, that his team could reach near 100% compliance.

To turn roach into a cyborg, a candidate is first put to sleep with CO2. An acupuncture needle is then used to puncture the mini-brain and insert electrodes. Then, a sort of glue is applied to the backside to stick a chip the size of a quarter. The chip communicates with a remote control that the researchers use to control the roach, but also sends other sensory inputs depending on what kind of hardware the roach is carrying (cameras, motion etc.).

Is this unethical and inhumane, however? The roach brain is primitive compared to a human brain, and as such the way it suffers is fundamentally different from our idea of pain. When asked if it hurts the roach, Texas A&M PhD student Carlos Sanchez jokingly said ” I don’t think so. I haven’t heard any complaints from them.” On more serious note, Sanchez went on to say that the connections  between their neurons and muscles are much simpler than hours, “so they probably don’t remember pain,” speaking for NPR. He is most likely right, but I can’t help noticing how this all sounds like a guess.

cyborg cockroach

Image: Texas A&M Engineering

A while ago, an educational company called Backyard Brains came under a lot of fire. The reason: the company sold remote controlled cyborg cockroaches. For 99$, the company sends you a kit with instructions on how to convert your very own roach into a cyborg for educational purposes – actually, it’s intended for kids as young as ten years old and the project’s aim is to spark a neuroscience revolution. Animal rights activists were furious, but the founders stress that the project bears important educational benefits. Kids can learn how important the brain is, how it functions, and so on. Moreover, kids are encouraged to take care of their cyborg roaches. When no longer needed, the roaches are sent to a retirement tank the scientists call Shady Acres where disabled insects go on to live the rest of their days. “They do what they like to do: make babies, eat, and poop.”

One could argue, however, that these animals need not suffer. Each animal suffers in an unique way – sophisticated or not – but it still suffers. For instance, crabs and lobsters do feel pain when boiled alive (big surprise!). On the other hand, despite animal research is quite unfortunate, most often than not it’s essential to developing new treatments and even education. This is why cutting edge science which focused on building accurate live models in cells or even simulations is so important. When these become truly accurate, maybe as far as replicating human biological responses, then animals might finally be spared from human meddling.

Back to cockroaches, few people know how extraordinary these creatures really are. Everybody knows they can survive nuclear fallout, but lesser known is that roaches make democratic group decisions, are master ninjas and even have a personality. If you move past seeing them as gross, roaches can be damn interesting, cute even.

Cockroaches have different personalities and characters, study finds

The cockroach – one of the nature’s great survivors, hated by building residents throughout the entire world, just got more interesting. According to a new study published in the journal Proceedings of the Royal Society B, cockroaches have individual and even group personalities; in other words, cockroaches do have a character.

“Cockroaches are a simple animal, but they can reach a complex decision,” said lead author Isaac Planas-Sitjà, a behavioral ecologist at the Free University of Brussels in Belgium, according to Reuters. “So with little information, with little interactions, only knowing if I have a partner here or not, only with this information, they can make complex decisions.”

Truth be told, cockroaches get a lot of needless bad rep – only 30 species out of 4,600 are associated with human habitats, and out of these, just four species are well known as pests. But those who are pests, are really hard to deal with; cockroaches are generally regarded as some of the most sturdiest species in the world, and for good reason. Some species are capable of remaining active for a month without food and are able to survive on limited resources, such as the glue from the back of postage stamps. Some can go without air for 45 minutes. In one experiment, cockroaches were able to recover from being submerged underwater for half an hour. The cockroach’s ability to withstand radiation is also well known, though they are not exceptionally radiation-resistant compared to other insects, such as the fruit fly.

Image via Globe Views.

Scientists chose cockroaches for this personality test because they don’t live in a clearly layered society, with leaders and workers. Planas-Sitjà and colleagues placed radio frequency identification chips to 304 roaches to track their movements when placed in a new environment, dividing them into 19 groups of 16 individuals. Three days a week, researchers would place each group in a brightly lit plastic area conceived as a shelter, and recorded how they behave. They noted that some cockroaches liked to stay in the shelters more, while others were more shy and didn’t enjoy spending time there. Some cockroaches were more bold and spent more time exploring the surroundings, while others took cover immediately.

“We have a group of equal individuals that reach a choice, can have consensus decision making as we can see in sheep, bats, some monkey species, fish, birds, for example, or also humans in this case,” said Planas-Sitjà.

The way individuals acted also affected group dynamics: if one roach was quick to settle under a shelter then it might encourage others to do the same, reducing the total amount of time needed to achieve the end result. This came as quite a surprise.

“The fact, and we didn’t expect it, is that they always reach this consensus,” Planas explained. “So we expected that some groups have more trouble than others to resist consensus or to choose a shelter, but at the end, no, they always finished aggregated. So it is something really inside the individuals or in the cockroaches. So that was really, that was amazing.”

It’s not the first time surprisingly complex behavior was reported in cockroaches. In 2014, a different team, also from Belgium, found that cockroaches make democratic group decisions. They presented 50 cockroaches with the choice of staying in two or three shelters, and they split equally (25 and 25) into two shelters; however, when they gave them a large enough shelter, they all shared the same shelter.

All in all, Belgium researchers seem adamant to show that cockroaches are much more complex than we previously thought, and they’re succeeding. The little insects deserve some recognition – after all, they do have character.


How cockroaches make democratic group decisions

For cockroaches, it seems, collaboration comes naturally: when 50 cockroaches are presented with 3 shelters which can only host 40 (each), they’ll split into two groups, leaving the third shelter empty. Basically, they find a way to split themselves equally, in a democratic fashion.

In cockroach groups, there are no members higher than others – everybody is equal, apparently. Thus, group decision making is simplified, leading to patterns which can be understood and studied. What makes it even more interesting is that cockroaches don’t make sounds, so they must therefore communicate without vocalizing.

“Cockroaches use chemical and tactile communication with each other,” says Dr José Halloy, who co-authored the research in the current Proceedings of the National Academy of Sciences. “They can also use vision,” says Halloy, a scientist in the Department of Social Ecology at the Free University of Brussels in Belgium. “When they encounter each other they recognise if they belong to the same colony thanks to their antennae that are ‘nooses’, that is, sophisticated olfactory organs that are very sensitive,” he says.

Halloy wanted to see how the cockroaches would behave when faced with a decision. He placed the insects in a dish that contained three shelters. Initially, the shelters could only host 40 insects each, so the 50 bugs decided to split equally – 25 into one, 25 into the other, leaving the third one empty. However, when the shelters were larger than 50, they all moved into just one shelter, showing that they make rational, democratic group decisions.

“Cockroaches are gregarious insects [that] benefit from living in groups. It increases their reproductive opportunities, [promotes] sharing of resources like shelter or food, prevents desiccation by aggregating more in dry environments, etc,” he says.”So what we show is that these behavioural models allow them to optimise group size.”

The way they behave is so basic and rational, that it can be quite predictable to model. Researchers hope to draw insights for other insects as well – and not only insects.

“It looks both at the mechanisms underlying decision-making by animals and how those mechanisms produce a distribution of animals amongst resource sites that optimizes their individual fitness,” says Dr David Sumpter, a University of Oxford zoologist.”Much previous research has concentrated on either mechanisms or optimality at the expense of the other.”

The study documenting this behavior was published in PNAS in 2006.

Backyard Brains

Is making cyborg cockroaches immoral?

Backyard Brains

(c) Backyard Brains

Through the halls of TedxDetroit last week, participants were introduced to an unfamiliar and unlikely guest – a remote controlled cyborg cockroach. RoboRoach #12 as it was called can be directed to either move left or right by transmitting electrical signals through electrodes attached to the insect’s antennae  via the Bluetooth signals emitted by a smartphone. Scientists have been doing these sorts of experiments for years now in attempt to better understand how the nervous system works and to demonstrate how it can be manipulated.

Greg Gage and Tim Marzullo – co-founders of an educational company called Backyard Brains and the keynote speakers at the Ted event where the cyborgroach was shown – have something different in mind. They want to send RoboRoaches all over the U.S. to anyone who’d be willing to experiment with them. For 99$, the company sends you a kit with instructions on how to convert your very own roach into a cyborg for educational purposes – actually, it’s intended for kids as young as ten years old and the project’s aim is to spark a neuroscience revolution.  Post-TedxDetroit, however, a lot of people, including prominent figures from the scientific community, were outraged and challenged the  ethical nature of RoboRoaches.

“They encourage amateurs to operate invasively on living organisms” and “encourage thinking of complex living organisms as mere machines or tools,” says Michael Allen Fox, a professor of philosophy at Queen’s University in Kingston, Canada.

“It’s kind of weird to control via your smartphone a living organism,” says William Newman, a presenter at TEDx and managing principal at the Newport Consulting Group, who got to play with a RoboRoach at the conference.

How does the RoboRoach#12 and its predecessors become slaves to the flick on an iPhone touchscreen? In the instruction kit, which also ships with a live cockroach, students are guided through the whole process. First the student is instructed to anesthetize the insect by dousing it with ice water. Then the insects head is sanded with a patch of shell so that it become adhesive, otherwise the superglue and electrodes won’t stick. In the insect’s thorax a grounwire is inserted. Next, students need to be extremely careful while trimming the insect’s antennae before inserting silver electrodes into them. Finally, a circuit fixed to the cockroach’s back relays electrical signal to the electrodes, as instructed via a smartphone Bluetooth.

Gage says, however, that the cockroaches do not feel any pain through out this process, though it is questionable how certain he is of this claim. Many aren’t convinced. For instance  animal behavior scientist Jonathan Balcombe of the Humane Society University in Washington, D.C.  says“if it was discovered that a teacher was having students use magnifying glasses to burn ants and then look at their tissue, how would people react?”

That’s an interesting question, but I can also see its educational benefits of course. It teaches students how quintessential the brain is and how it governs bodily functions through electrical signals. Scientists, unfortunately, heavily rely on model animals like mice, worms, monkeys and such for their research. These animals certainly suffer, but until a surrogate model is found the potential gain convinces most policy makers that this practice needs to continue , despite the moral questions it poses. Of course, this kind of research is performed by adults, behind closed doors, in the lab – not by ten year old children. Also, what about frog dissections in biology classes? Some schools in California have banned the practice entirely, should other schools follow suit?

What happens to the roaches after they’re ‘used and abused’? Well, they go to a roach retirement home, of course. I’m not kidding. Gage says that , all students learn that they have to care for the roaches—treating wounds by “putting a little Vaseline” on them, and minimizing suffering whenever possible. When no longer needed, the roaches are sent to a retirement tank the scientists call Shady Acres where disabled insects go with their lives. “They do what they like to do: make babies, eat, and poop.”

Gage acknowledges, however, that he has indeed received a ton of hate mail. “We get a lot of e-mails telling us we’re teaching kids to be psychopaths.”

It’s worth nothing that cyber roaches are being used for some time in research. Scientists  in North Carolina are trying to determine if remote-controlled cockroaches will be the next step in emergency rescue, for instance. The researchers are now hoping that these roaches will be able to be equipped with tiny microphones and navigate their way through cramped, dark spaces in effort to find survivors in disaster situations.

So, ZME readers, what do you think? Should Cyber

Mutant cockroaches learn to avoid sugar traps

Cockroaches, the blight of every urban apartment; they’re adaptable, they’re sturdy, and they reproduce really fast. The nasty, disease carrying bugs can eat pretty much anything they find around the house, from mold and rotten food to the thing they love the most – sugar.

cockroachWhen given the opportunity, cockroaches always go for the sugary treat – or at least they used to. According to a new study published in Science, some cockroaches have evolved to the point where they are actually refusing to eat sucrose, a form of sugar commonly found in plants.

“They now perceive glucose as bitter,” says Coby Schal, an entomologist at North Carolina State University and one of the report’s authors.

Why did this happen? Well, glucose is the main thing that attracts them in traps, and many of the little creatures have mutated so that they actually don’t like it anymore. They mutated so fast that it took everybody by surprise.

Back when prehistoric cockroaches lived in the wild, there’s a possibility that they didn’t gobble glucose as well, because many plants that contain it in the wild are poisonous – but that’s still debated.

However, as humans evolved and moved to caves, cockroaches were soon to follow. Away from the threat of poisonous plants, they started to develop a taste for sugars, because it is a highly nutritious source of energy, and it was to their advantage to consume it.

But the mutation remained in their gene, and when humans started putting sugar traps, we reactivated the old gene – so much that when we put sugar in front of (some groups of) cockroaches, they just “jump back as though you’ve given them an electric shock“.

Apparently cockroach researchers take their job pretty serios, and they want to dedicate the next decade or so to studying this adaptation.

“We have roaches in the freezer that date back to the 1930’s,” says Schal. “This is what’s going to be driving our research over the next five or ten years.”

But all hope of trapping these mutant critters not lost. Sucrose-averse roaches are still attracted to fructose, or fruit sugar, and maltose, which is found in beer (“they really love that stuff,” says Schal).



What cockroaches can teach us about balance


Cockroaches are maybe the most amazing insects in the animal kingdom – they’re simply made to survive. These little buggers can survive in sub-zero temperatures, can withstand a lethal dose of radiation up to 15 times of that for humans, can live without food for a whole month and … they can live with a severed head for up to a week. The last instance is of particular relevance to the article at hand, since scientists at University of California, Berkeley have found that cockroaches balance themselves without using their brains. Practically, the insect’s legs have a mind of their own.

Shai Revzen, now an assistant professor of electrical engineering and computer science, and colleagues sought to find out just how cockroaches keep their balance and devised an experimental set-up comprised of a tray that wiggled in different directions as a result of an  elastic that stretched and contracted. The cockroach that was placed on the tray would immediate re-balance itself as soon as the tray zoomed in one direction or another.

Using high speed cameras and a computer to trace where exactly the cockroach stepped, the scientists found that the insect made its adjustments  at the end of a step, instead of in the middle. What this means is that the roach’s nervous system was relying on continuous feedback from the cockroach’s surroundings, and that it didn’t receive instructions from the brain. A separate experiment that used electrodes attached to a cockroach’s leg confirm these findings as well.

This behavior is truly remarkable, and scientists designing robots can learn a great deal from the mighty roach. If you’ve interacted with a robot or two before then you know how clumsy they can be and how truly difficult it is for them to simply stay on their “feet”. Adaptability is a great challenge for robot designers worldwide. All current motor designs are based on instructions sent and received by the “robot brain” via sensors in a robot’s legs for instance. The cockroach however keeps the brain out of the equation and does this one step at a time.

What about humans? Well, the curious thing is that scientists still aren’t sure how our legs control walking – a very complicated motor and nervous activity. After scientists learn how our legs respond to the outside environment and just how exactly the nervous system coordinates walking, expect a new era of extraordinary prosthetic limbs and therapies for people suffering from brain injuries to unfold.

Findings were published in the journal Biological Cybernetics.

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Tap into the cockroach’s neural activity with the SpikerBox

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insert neural node here

Neurons are the absolute core components of the nervous system that transmit information through electrical and chemical signals. I once wondered how neural activity might sound like, and I imagined something like a huge gridline sprinkled with electricity bolts though out. I didn’t know about the SpikerBox, back then, though. It’s a gadget, developed by educational entrepreneurs Timothy Marzullo and Gregory Gage, which can measure the neural activity of various insects and can be employed in some very interesting experiments, like observing how neural activity is affected by temperature, external electrical signals or … pokes. Beware, you need to cut off a cockroach leg for science!

It’s a very simple set-up made out of a microprocessor,  two neural probes, and a speaker, everything powered by a 9V battery. In a demo video for the gadget, its creators explain how it works and how to use it. Just find an invertebrate, like an insect, from under your local rock, cut off one of its legs (it grows back). Then stick one of the needle probes in the femur, and the other a bit higher on the leg. What you’ll hear next is the electrical activity of the still living neural network in the leg. If you’re looking for some graphical representation as well, the device can be tethered to an iPhone or Android phone. Find out more about the SpikerBox at Backyard Brains.