We all know too well how easily things get dirty. Dust gathers, and stains appear, seemingly out of nowhere. That’s no exception for the Animal Kingdom, either. But for some of these critters, staying clean isn’t just a matter of being comfortable. It’s also a matter of survival.
The question of how animals manage to stay squeaky clean is something that researchers from the Georgia Institute of Technology dug into in 2015 — and certainly, there are quite a few inventive evolutionary methods at hand. Cicadas, for example, sport wings with posts so tiny they’re invisible to the naked eye, which puncture and pop incoming bacteria like balloons, while bees, whose hairy bodies have as much surface area as a slice of bread, flick clumped pollen off their hairs like springboards.
Some animals, though, are more known for dirt and grime than others. Here are four animals who may have unfairly nasty reputations that take care to clean themselves up, much like the rest of us.
1. Rats Have Grooming Routines
Rodents, particularly rats, get a bad rap, especially considering their historical linkage to disease outbreaks like the Black Death. While rats did play a role in spreading the plague, scientists have argued that the poor sanitation and environmental conditions of the era had a much larger hand in the resulting death toll.
Since those days, rats have come a long way. They’re even considered common household pets now, thanks to their relatively larger size and chill personalities. One of the most frequently performed activities that rats partake in, according to researchers, is in fact, grooming themselves.
Rats have even developed set sequential stages in their grooming techniques, steps that might resemble our own shower and skincare routines. Youngsters typically start out their lives by only grooming their faces, but as they age, they eventually move on to cleaning up their entire bodies.
Read More: A Tiny, Welsh Mouse Likes to be Clean and Tidy, and so do Other Animals
2. Ants: Some of the Cleanest Insects
You may get grossed out after spotting an ant (or several) crawling over days-old leftovers or spilled sweets, but ants are actually considered some of the cleanest insects out there, according to Texas Parks and Wildlife, for a number of reasons. Grooming and licking fellow ants in the colony, for one, is a social activity for the bugs, and one of the major responsibilities of nurse ants is keeping eggs and larvae clean.
Much like other insects, keeping tidy is a matter of survival for ants. They rely on their antennae for detecting pheromones, communication, and getting around. While dust particles might just be tiny and annoying inconveniences to us, too many gathered up on antennae can end up obstructing entire sensory pathways and navigation systems.
These organs are so important, in fact, that scientists have found ants evolved their own micro combs on their front legs in order to clean their antennae. Clamping their antennae in these contraptions, ants then pull it through in order to rake off offending foreign materials – somewhat similar to how we might use a lint roller to get fur off our clothes.
Moreover, the cleaning structure on ants’ legs is made up of a combination of different types of hairs, functioning like both a comb and a brush to systematically pick up and remove tiny particles. The hairs within this structure are even arranged to target differently sized particles, filtering from largest to smallest.
Read More: How Smell Holds Ant Societies Together
3. Opossums Clean up the Streets
Some researchers consider opossums to be a misunderstood marsupial, viewed as either lazy or dirty, or both. After all, their diet consists in part of carrion, as opossums scavenge among carcasses as well as hunting other small mammals. Also famously, they play dead, secreting a stinky substance in their comatose state to further ward off predators.
Like other animals, however, opossums have their own self-grooming routine, tidying up with their tongues and paws. Scientists, however, argue that possums can keep more than just themselves clean. A 2023 study found that opossums can also help clean up our cities, ridding them of rodent carcasses that, if left untouched, can pose biological hazards to humans.
Opossums are happy to munch on even days-old leftover roadkill, suggesting their bodies are strong enough to overcome the accumulating decay and bacteria. Considering opossums tend to be distributed around these more populated urban centers anyway, the study authors argue they can perform a vital health service for us by cleaning up the streets in their own way.
Thanks to their lower body temperatures, opossums also can’t spread rabies – though some researchers warn that they do have the potential to spread diseases to humans, via ticks on their bodies. But, the authors of the 2023 study argue that opossums should not only be considered as reservoirs of potential disease, writing, "The services provided by this animal may greatly outweigh the potential disease transition."
Read More: Instead of Dozing Off, These Marsupials Are Too Busy… Getting Busy
4. Pigs Have Their Own Cleaning Standards
Last but not least is our friend from the farm, the pig. They might be some of the most well-known "dirty" animals whose reputation for muck precedes them. After all, pigs enjoy wallowing around in mud pools. If we leave our living spaces unattended for too long, we call them "pigsties."
But in their natural history and in the wild, pigs are actually highly intelligent animals who maintain their own standards of living and cleanliness.
What first needs clarification is that the mud-rolling happens because pigs, who are unable to sweat, need a way to keep cool. But, contrary to the popular conception that pigs will laze not just in mud but also their own feces when given the opportunity, pigs will actually separate their bathrooms from their living spaces. This happens for a number of reasons that might include preventing disease spread, marking their territories, and a general desire for good hygiene.
It was the rapid industrialization of agriculture that eventually led to the poor conditions in which pigs tend to live now — crowded, dark, smelly pens without the ability or physical room to separate excrements from the rest of the environment.
Given the discrepancy between their current living conditions and natural inclinations, some researchers are advocating for the development and implementation of features like pig toilets within their pens — the equivalent of staking out a bedroom conveniently located right by a bathroom.
Read More: Arctic Bumblebees Use Outhouses to Keep Nests Clean
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Journal of Experimental Biology. Cleanliness is next to godliness: mechanisms for staying clean
Science News Explores. Don't blame the rats for spreading the Black Death
Ferrets, Rabbits, and Rodents. Rats and Mice
Nature reviews. Neuroscience. Neurobiology of rodent self-grooming and its value for translational neuroscience
Texas Parks and Wildlife. Nature's Bath Time
Royal Society Open Science. Functional morphology and efficiency of the antenna cleaner in Camponotus rufifemur ants
Wildlife Animal Control. Why do Opossums Play Dead?
National Park Service. Opossums
Mammalia. Opossums cleaning our cities: consumption of rodent carcasses in an urban reserve
Ticks and Tick-borne Diseases. Are Virginia opossums really ecological traps for ticks? Groundtruthing laboratory observations
PBS. Pig Facts
Animals: an open access journal from MDPI. Soiling of Pig Pens: A Review of Eliminative Behaviour
