Tag Archives: feces

Honey bees use tool made of poop to repel giant hornet attacks

Bees are remarkably intelligent creatures capable of abstract thought (they can count and grasp the concept of zero) and use symbolic language. But that’s not all. In a new study, researchers have shown that honey bees (Apis cerena) in Southeast Asia are collecting animal dung to defend their colonies from potentially devastating giant hornet attacks. This is the first time tool use has been documented in bees.

Honey bees apply animal feces at the entrance of their hives to ward off attacks from giant hornets. Credit: Heather Mattila/Wellesley College.

While working on other projects in Vietnam, Gard Otis, a professor at the University of Guelph who specializes in honeybee behavior and co-author of the new study, noticed fecal spotting on some hives. Upon investigating, he learned from beekeepers that the bees were reacting to attacks by the giant Asian hornet (Vespa soror). One of the beekeepers even said that he witnessed worker bees foraging on dung in water buffalo fields. That got everybody’s attention and it turned out it was true.

“We first determined through observation that bees were in fact foraging for animal dung, carrying it back to their hives, and then applying it around their entrances,” Heather Mattila, associate professor of biological sciences at Wellesley College and co-author of the study, told ZME Science.

“Through a series of field trials, we figured out that Asian honey bees started spotting after their colonies experienced naturally occurring visits by V. soror, they would continue to spot for days (even after attacks ceased), and they spotted even if they were presented with only the glandular extracts that the giant hornets use to mark colonies as targets.”

“However, fecal spotting was the strongest if the colonies were exposed to real hornets.  We also determined that colonies didn’t spot in response to attack by Vespa velutina, a smaller hornet that is not as strong a predator and hunts without coming into contact with hives or nests.  Finally, we determined that V. soror, the giant hornets, were much less inclined to try to break into colonies that were moderately or heavily spotted, thus limiting their ability to execute group attacks, which can result in devastating colony takeovers.”

Although honey bees are famous for foraging materials produced by plants, such as nectar and pollen, they had never been seen retrieving solid material from any other source until now.

Mattila and Otis have been studying giant hornets and Asian honey bees in Vietnam for several years, conducting fieldwork in apiaries with colonies housed in wooden hives managed by local beekeepers.

“In the early stages of the study, we spent a few days hanging out on farms and seeing if we could find bees foraging on livestock dung.  Eventually, after sitting in a chicken coop for a few hours, I was able to take a few dimly lit videos of bees collecting chicken dung, so it was a very exciting moment.  I remember running back to our study apiary, bursting with the news I wanted to share with everyone, that we had finally confirmed that bees were collecting dung. After that, we brought piles of dung to the side of our most active apiary and we were able to observe many more bees collecting it,” Mattila wrote in an email.

After the researchers confirmed that the bees were collecting animal dung, they then cleaned the colonies to track how exactly the bees were designing their defenses using fecal spotting. As they monitored the bees’ behavior, they observed how giant hornets were repelled from nest entrances, where they focus their attacks.

This seems like an innate behavior, “just like how taking up foraging for other things, like food from flowers, is instinctual,” Mattila said. “Bees learn a lot as individuals as they forage, like how to become more efficient as they do it, but it is unlikely that the fecal spotting strategy is a culturally transmitted defense,” she added.

As for why the hornets find the feces so repelling, scientists aren’t sure yet. But since it acts like a chemical weapon, it’s likely that specific chemical properties keep hornets away, while not affecting bees in any negative way.

“At this point, we know little about how the foraging effort for dung collection is organized.  We know from research conducted in Japan, where this honey bee species has been documented collecting plant material in response to hornet attacks, that bees perform what are called “emergency dances” to boost foraging.  We saw the same kinds of dances performed outside of some of our study hives, but a lot of work remains to be done to figure out how bees organized this process, as well as what exactly workers are seeking from dung when they go foraging,” Mattila said.

“Many scientists disagree over whether certain animals, let alone insects, use tools,” Otis said in a press release. “To qualify as tool users, animals must meet several criteria, including using an object from the environment–in this case, dung. The bees clearly use the material to alter the hive with purpose, in addition to meeting the requirements of holding or manipulating the tool.”

In the future, the researchers plan on conducting more follow-up field studies that examine the acoustic signals shared by workers when they are under attack by hornets. However, because of travel difficulties due to the pandemic the researchers had to postpone travel. Instead, they’ve sent hornet samples to colleagues to “figure out more about how the hornets mark colonies for attack.”

“Our study adds another defense to the already impressive list of ways that Asian honey bees fend off attacks by hornets, and especially giant hornets, which are particularly deadly predators.  It also makes clear why honey bee species that haven’t evolved with these predators are so vulnerable to their attacks because they lack these important defenses that result from exposure to this predatory pressure over evolutionary time,” Mattila concluded.

The findings appeared today in the journal PLOS ONE.

Wastewater analysis can reveal how wealthy, healthy, and well-fed you are

New research from the Queensland Alliance for Environmental Health Sciences in Australia is taking a very unusual approach to understanding the people in different communities: analyzing their sewage.

Image via Pixabay.

The team reports that varying income levels in different communities are linked to different food and drug consumption habits. While that conclusion itself isn’t exactly surprising, the way the team reached it is. This is the first study of its kind to show that these habits result in noticeable differences in the wastewater of individual groups of people.

Data dump

Preivous studies have shown that our drug consumption shows up in wastewater — but this is the first study to track other lifestyle traits using the same approach.

“Although [wastewater-based epidemiology] has primarily been used for measuring drug consumption, our results demonstrate that it can be used to identify sociodemographic patterns or disparities which associate with consumption of specific chemicals or food components,” writes the team, led by Phil Choi, a Ph.D. student at the Queensland Alliance for Environmental Health Sciences in Australia.

Wastewater from wealthier communities, where people had higher educational achievement, showed higher levels of vitamins, citrus, and fiber, the team reports. Wastewater from poorer communities, where people were overall less educated, showed higher levels of prescription pain relievers and antidepressant medications. Wastewater analysis can thus be used to gain insight into the consumption habits of individual communities, the paper concludes.

The study examined samples from 22 water treatment plants from six Australian states over seven consecutive days in 2016. The results were compared to 40 different socioeconomic factors from Australia’s national census (factors such as rent price and education level). Choi’s team then drew correlations between these factors and compounds found in the urine and feces of residents.

One of the strongest correlations the team identified was between socioeconomic status and prescription drug use. Wastewater treatments plants that serve areas associated with lower overall socioeconomic status had higher levels of several prescription drugs in their wastewater. These drugs are:

  • tramadol, an opioid pain reliever;
  • desvenlafaxine, an antidepressant;
  • mirtazapine, an antidepressant;
  • pregabalin, a prescription pain reliever;
  • atenolol, a blood pressure drug.

While people of lower socioeconomic status do report higher drug use than others, the team notes that the study shows their method is useful to analyze overall trends in a community.

Wealthier and healthier

Dietary fiber and citrus consumption were also strongly correlated with socioeconomic status — an indication that the wealthier households had an overall better diet. Wastewater from wealthier areas also had higher levels of proline betaine, a component of citrus flesh. Enterodiol and enterolactone, which are components found in the waste of people who eat plants, were also found in higher concentrations than in the wastewater of other areas, the team reports. These results suggest that people in wealthier communities mix more fresh fruit and vegetables in their diet.

Areas with higher overall rent rates — those over $470 a week — wastewater contained significantly higher levels of vitamins B3, E, and B6. The researchers identified these compounds by looking for their metabolites (what’s left after our bodies process a particular substance) in wastewater. Areas with the lowest rent rates — areas where people of lower socioeconomic status live — showed lower levels of these vitamins in their wastewater.

The study aims to showcase the role that wastewater-based epidemiology can play in efforts to monitor public health and illicit drug use. There is an ongoing debate on the merits of this field of research, the team notes, revolving particularly around the issue of privacy (the method can be used to gather data on people without their consent). For the moment, however, the findings confirm previous results on the relationship between socioeconomic status and health — richer people eat better and have fewer health issues, the team explains.

The paper “Social, demographic, and economic correlates of food and chemical consumption measured by wastewater-based epidemiology” has been published in the journal PNAS.

Business students are more likely to have a brain parasite infection spread by cat feces

Credit: Pixabay.

Students in the US who are infected with a weird brain parasite commonly spread by cats are more likely to major in business studies, according to a new study. The findings suggest that the infection may be promoting entrepreneurial tendencies by reducing fear and enhancing risk-taking behavior.

Toxoplasma gondii is a parasite carried by cats and found in their feces, but which can also be acquired after consuming poorly cooked meat or contaminated water. A third of the world’s population is thought to be infected with the parasite.

Once it infects a human host, the parasite can cause toxoplasmosis, which is the leading cause of death attributed to foodborne illness in the United States. More than 60 million men, women, and children in the U.S. carry the Toxoplasma parasite, but very few display symptoms because the immune system usually keeps the infection from causing illness.

But even though they might not feel sick, Toxoplasma-carrying individuals may experience changes in their behavior induced by cysts in the brain formed by the parasite, which can remain for the rest of an individual’s life.

Lifecycle of T. gondii. Credit: Wikimedia Commons.

Lifecycle of T. gondii. Credit: Wikimedia Commons.

Jaroslav Flegr, a Czech evolutionary biologist, claims that the parasite is quietly tweaking the connections between our neurons, changing our response to frightening situations, our trust in others, how outgoing we are, and even our preference for certain scents.

A reduced response to fear seems to be a common occurrence. Studies conducted by Stanford’s Robert Sapolsky on rats infected with Toxoplasma showed that rodents actually turned their innate aversion to felines into attraction, luring them into the jaws of the predator. Basically, the parasite carried by the cat brainwashes the rat — and perhaps human owners too, some claim —  to become attracted to the feline.

An assessment of nearly 1,300 students from the US also found an association between exposure to the parasite and reduced fear response. The students who were exposed to the parasite were 1.7 more likely to be majoring in business studies. Particularly, they were more likely to focus on management and entrepreneurship than other business areas.

What’s more, the researchers found that individuals who attended business events were almost twice as likely to start their own business if they were infected by Toxoplasma gondii. Countries with a high prevalence of Toxoplasma infection showed more entrepreneurial activity, according to the results published in the Proceedings of the Royal Society B.

The parasite may be reducing a person’s fear of failure and promoting risk-taking behavior — the kind of fearless mindset that is generally required of entrepreneurs. Of course, that doesn’t mean that infected individuals are actually more successful entrepreneurs — most businesses actually fail within their first five years of activity and a poorer risk-evaluating ability induced by the parasite infection might actually be extremely detrimental to business activities.

Pee, Poop, and Perspiration Will Be Useful in Traveling to Mars

People have effectively been able to acquire fuel and, consequently, energy from human urine. This capability has been known for a number of years. In late 2012, a small group of teenage girls from Nigeria made the news by presenting a generator that ran on urine at the Maker Faire Africa. In their generator, the pee is poured into an electrolytic cell where the hydrogen is isolated from other components in the liquid.

The hydrogen is then purified by passing through a filter. From there, it’s sent to a gas cylinder from which it is further pumped into a cylinder containing liquid borax. The borax aids in separating the hydrogen gas from any remaining moisture. The final step is for this gas to be sent to the generator. The girls’ machine was able to supply six hours’ worth of electricity by using a mere liter of liquid waste.

Of course, this was a rather simple apparatus primarily for display, but the important thing is it worked! Urine’s use for producing gas and/or syngas (synthesis gas) has the potential to be quite revolutionary.

Waste as a Water Source in Space


Credit: Wikimedia Commons.

Recycling everything possible in extraterrestrial day-to-day life and travel saves both space and money. For a while now, astronauts on the International Space Station have been recycling their own perspiration and pee. The purified output is clean water, which is drunk a second time over. This cycle can be repeated over and over.

You’ve heard of twice-baked potatoes? Well, twice-expelled waste is starting to catch up in its popularity. Human urine and condensate (including breath moisture, human sweat, shower runoff, and animal pee) are all distilled and reverted to clean drinking water. As of 2015, about 6,000 extra liters of water are recycled each year.

Waste Empowering Yeast

One of the molecules which makes up our urine is called urea. Furthermore, urea is composed of nitrogen and carbon. Both of these chemicals are needed to feed a yeast, Yarrowia lipolytica, which when genetically tweaked properly can take a variety of forms such as bioplastics and even fatty acids. One particular fatty acid necessary for human health and functionality is Omega-3. The brain requires this nutrient.

Thus, Yarrowia lipolytica is being tested to hopefully be able to produce Omega-3’s efficiently in the future. This would be a great aid to humanity in the occasion of a manned mission to Mars or elsewhere. In addition, future astronauts will use 3D printers onboard their spacecraft to generate tools and other needed objects made of plastic. Yet again, the yeast can be altered to produce a certain type of polyester which could be employed for this purpose.

Feces and Urine for Future Food

The sheer quantity of food needed to sustain a manned mission to Mars remains a big problem. However, a clever party of researchers from Pennsylvania State University believes to have found an efficiently ingenious answer. The concept was discussed in a paper published in late 2017. Their space-saving device, a bioreactor, uses the urine as well as the feces of astronauts to feed a non-harmful bacteria that, in turn, is capable of sustaining the human space travelers.

Within the bioreactor, the solid and liquid waste become condensed leaving salts and methane gas in its place. It’s the methane which is used to grow the microbial mush, an edible element with a texture similar to that of Vegemite, a thick Australian spread made up of leftover brewers’ yeast extract along with an assortment of additives.

As you have seen, our astronauts’ waste will not be wasted. Scientists will surely engineer more ways for bodily waste to be put to beneficial use.


Cancer tumors destroyed by fecal bacteria

Scientists introduced Clostridium novyi, a bacteria that causes mild illnesses in humans that typically lurks inside the soil and feces, in cancer tumors and found that these shrank and some cases were destroyed completely. The research suggests that bacteria, when engineered to reduce toxicity, can be a viable fighting tool against cancer, one with less destructive side effects than chemotherapy.

Killing cancer with bacteria


Image: Spore Coat Architecture of Clostridium novyi NT Spores. Source: Journal of Bacteriology

Dr. Shibin Zhou and colleagues at  Johns Hopkins University first became interested in bacteria as a potential cancer treatment some ten years ago after reading the archaic works of New York doctor William Coley, who 100 year ago reported patients sometimes went into remission after they contracted a serious bacterial infection. Coley then isolated bacteria and inserted it into patients in hope that he might replicate what he observed. The challenges he come across were numerous, like making patients more ill than they were before treatment. Then,  chemotherapy and radiation therapy started to become popular and scientists lost interested in anti-cancer bacteria.

The researchers first made sure they genetically modified the bacteria to make it less toxic, then used it to infect tumors (direct injection) that were growing in live patients: 16 pet dogs and one human. The human patient’s tumor that was treated with bacteria shrank, while other tumors in the patient’s body continued to grow. Three of the dogs were cured of cancer completely, and three others saw their tumors shrink by at least 30 percent.

One important caveat about C. novyi is that it only operates in oxygen-free (anerobic) environments. This held true when researchers found some of the tumors who supported oxygen didn’t show any sign of shrinking. Some drugs work by cutting off the tumor’s blood supply — and, with it, oxygen. Complementing these drugs with engineered bacteria might render some extremely promising results, yet more tests are required before any dramatic claim is voiced. Also, there’s a concern that some bacterial infections can cause cancer, though there’s no evidence that C. novyi itself is involved.

C. novyi isn’t the first bacteria to offer promising anti-cancer prospects. Dartmouth-Hitchcock Medical Center researchers used a genetically modified strain of a parasite that dwells in cat feces to treat cancer in mice. Considering the parasite in question also causes toxoplasmosis, a condition thought to cause humans to go insane, some people might show reluctance for opting this treatment. Some viruses, like measles, have also been shown to shrink tumors.

The findings appeared in the journal Science Translational Medicine.