Buzz
While most of us would prefer not to think about vomiting, it actually has some unique and surprising roles in the animal world. From strengthening social bonds to warding off predators, the surprising uses of vomit are diverse. Let’s dive into some of the strangest and most clever ways vomit is used in nature.
10. Hyenas Enjoying Themselves
When you vomit, you probably rush to clean it up—not just because it’s unpleasant, but also to prevent spreading the illness that made you sick. However, the spotted hyena takes a different approach. This resilient animal boasts a powerful immune system that helps it fend off diseases like rabies, canine distemper, and even anthrax. Its favorite pastime? Rolling in vomit—both its own and that of others.
A biology student from Michigan State University elaborates on this behavior in vivid detail on the MSU Hyena Research blog. She explains that hyenas enthusiastically push each other aside to roll in vomit whenever a member of the pack throws up. Even the oldest hyenas will rush to join in, with one researcher humorously describing the scene as 'sliding into a very stinky home plate.'
9. Defensive Tactics of Turkey Vultures
Vomit may disgust most humans, but this aversion is shared across much of the animal kingdom. The turkey vulture takes advantage of this natural repulsion by projectile vomiting at any animal that poses a threat or disturbs it. It can project its vomit as far as 10 feet (3 meters) to deter potential predators.
The turkey vulture’s unsavory behavior goes beyond projectile vomiting. After feasting, these birds often defecate on their own feet. This practice, though off-putting, serves an important function: it helps cool their feet and acts as a natural antiseptic, killing bacteria they may have picked up from scavenging decaying meat.
8. Bald Eagles and Their Taste for Turkey Vulture Vomit
Thomas Jefferson’s choice of the bald eagle as the national symbol of the United States is well-known, yet the majestic bird is not the fearless hunter it appears to be. Descended from vultures, bald eagles are more scavengers than hunters, often stealing prey from ospreys and other predators. In fact, Benjamin Franklin considered the bald eagle too cowardly to represent the new nation, favoring the humble turkey instead for its less flashy, but admirable qualities.
Fish scavenged from the wild makes up a large part of the bald eagle’s diet, but the bird has a taste for more unusual fare. These intimidating creatures also favor turkey vulture vomit and will go to great lengths to obtain it. Bald eagles have been known to harass turkey vultures until they are forced to projectile spew, turning the regurgitated meal into an easy prize.
7. The Gory Act of Regurgitating Flies
You've likely heard that house flies regurgitate on human food, but the reality is far more unpleasant. According to researchers at the University of Massachusetts Amherst, the vomit of a house fly can contain all sorts of unsavory things, like rotting roadkill, trash, and even animal feces.
House flies have a special internal organ called a crop where they store food before digestion. When it's time for their next meal, they engage in a process called “bubbling.” Bubbling involves vomiting out excess water from the crop to create room for another bite, much like loosening your belt after a hearty meal. Unfortunately, this means that undigested food, sometimes feces or sewage, can be vomited along with the water, making your sandwich a lot less appetizing.
Researchers have discovered that house fly crops contain very few digestive enzymes or peptides to kill harmful bacteria. Additionally, the bacteria in a fly's crop are more likely to develop resistance to antibacterial treatments. While there's still much to learn about fly vomit, it's definitely a good idea to keep food covered and safe from these little pests.
6. Attracting a Mate
When it comes to romantic gifts, most people might think of flowers, chocolates, or jewelry. However, for Drosophila subobscura, a type of fruit fly native to the Mediterranean and now found in Europe, the Near East, and parts of the United States and Canada, the males offer something more unusual—a 'nuptial gift' of regurgitated liquid. Research shows that the more vomit the male offers, the higher his chances of successful mating. Additionally, consuming these vomit gifts even boosts fertility in females who are in poor health.
Fruit flies aren’t the only creatures to use vomit to attract a mate. A crustacean known as an ostracod has an organ specifically for creating bioluminescent compounds that attract females. To impress potential mates, the ostracod contracts the muscles around its organ, releasing glowing jets of the compound from its mouth. Some males even exploit another male's light show, taking advantage of the display without producing their own.
5. Puking Nestlings
If you’ve ever experienced a terrifying moment that made you feel like vomiting, you’ll understand the behavior of baby Eurasian rollers. These nestlings eject foul-smelling orange vomit when they sense danger. Scientists believe this act is partly a defense mechanism, but it also serves to alert their parents to the presence of nearby predators.
So, how do adult Eurasian rollers react when they detect their offspring's distress? According to Spanish scientists, they prioritize their own safety. The parents typically avoid feeding their young and stay away from the nest until the smell of the vomit fades. However, it's important not to be too harsh in judging these roller parents. If they were to fall prey to a predator, their offspring would be left without anyone to feed them, so this behavior might actually increase the chances of some of their babies surviving.
4. Stomach Rinsing
When you can't vomit in the usual way, it's helpful to have another method for removing indigestible food or other unpleasant substances from your stomach. Several species can expel their entire stomachs through their mouths in a process called eversion. While scientists are still unsure of the exact mechanics, it’s believed that these creatures relax the muscles that support their digestive system while increasing abdominal pressure to achieve this remarkable feat.
For stingrays, stomach eversion helps them rid themselves of unwanted debris, such as shells, large fish pieces, and mucus. Chinstrap penguins, on the other hand, use the process to expel excess fluoride from their stomach linings. However, frogs and toads provide perhaps the most unusual example—these creatures use their right hands to wipe the inside of their stomachs clean.
Why the right hand? This intriguing question caught the attention of Delilah Foss, a writer at Improbable Science. Determined to discover whether frogs and toads are indeed right-handed, she reached out to Richard Wassersug at Dalhousie University for answers. It turns out that when frogs and toads invert their stomachs, they always hang slightly to the right outside the mouth, solving the mystery of their apparent right-handedness.
3. Morning Sickness
Pregnancy can bring discomfort, with morning sickness affecting about two-thirds of women in the first trimester. Despite its name, “morning sickness” is often not limited to the morning hours; nausea and vomiting can occur at any time throughout the day or night, often making the first 12 weeks a challenging period for expectant mothers.
At first, it may seem that morning sickness is a biological oversight—after all, vomiting your meals seems counterproductive when nutrition is crucial during pregnancy. Surprisingly, though, this phenomenon may actually serve a protective function for both the developing fetus and the mother. A 2000 study by scientists at Cornell University found that morning sickness not only lowers the risk of miscarriage but that vomiting itself offers more protection than just feeling nauseous. But why is this the case?
The researchers suggest that vomiting reduces the likelihood of contracting a food-borne illness. Given that pregnancy weakens the immune system to prevent the body from rejecting the embryo, food poisoning is much more dangerous during this period—particularly between weeks six and eighteen when the baby’s development is most vulnerable. This is likely why pregnant women develop aversions to foods that are more likely to harbor harmful pathogens, such as meat, chicken, and fish.
2. Making Honey
The notion that honey is simply bee vomit might be enough to ruin your appetite. Thankfully, this common misconception is inaccurate, though it’s not entirely without a kernel of truth.
So, if honey isn’t bee vomit, what is it exactly? To answer that, let’s take a look at our buzzing friend, the housefly. Like houseflies, bees have a special storage area for nectar known as a crop. A membrane in this crop keeps food from passing through the bee’s digestive system, so rest assured, there’s no bee puke in your jar of honey.
However, the real action takes place inside the crop, often referred to as the ‘honey stomach,’ which is quite fascinating. The bee’s saliva releases enzymes that transform starches into sugars and create hydrogen peroxide to keep bacteria at bay. The crop also has a bristled valve that functions like a broom, removing unwanted pollen and parasitic spores from the nectar.
At this point, the process becomes a bit more regurgitative. The bee vomits the honey to another bee, which does the same thing, each time adding more enzymes. This back-and-forth continues, with bees swallowing and regurgitating the nectar until it reaches the right consistency. Once it’s ready, the bee pumps it into the honeycomb and uses its wings to fan away excess moisture, drying the nectar into the thick, sticky honey we all know.
1. Feeding Friends
Vampire bats lead surprisingly intricate social lives, forming complex relationships that play a key role in their survival. One of the more unusual aspects of their interactions involves sharing regurgitated blood meals by vomiting into each other’s mouths.
While scientists have been documenting vampire bats sharing regurgitated blood since the 1980s, recent studies have revealed that this practice helps ensure the survival of both the bat offering and the bat receiving the blood. Gerald Carter, from the Smithsonian Tropical Research Institute, spent three years observing captive bats in a Michigan zoo to unravel how this peculiar behavior functions as a type of social currency.
Carter’s research began with tracking which bats offered vomited meals to others. He then isolated certain bats for 24 hours without food and reintroduced them to the colony. By observing who was generous with sharing food, he uncovered a ‘tit-for-tat’ dynamic resembling human reciprocity. Female bats that had been more generous in the past received more regurgitated meals than those with a history of selfishness, with many bats refusing to feed individuals who hadn’t previously helped them.
