The presence of ants—say, in your sugar bowl, or crawling along the kitchen counter—might gross some people out, signaling an untidy environment. But ants are actually pretty cleanly creatures—particularly when it comes to their bathroom habits.
According to a paper published this week in PLOS One, black garden ants follow a specific etiquette when it comes to expelling their own waste. Rather than doing the deed any old place in their nests, they maintain one to four "well-defined faecal patches"—in other words, designated toilet areas. These makeshift bathrooms are exclusively used for ant excretion, to the exclusion of all other waste, such as corpses and uneaten food.
This never-before-studied behavior was witnessed by scientists examining 21 lab-grown colonies of black garden ants, which are a common species found across Europe and parts of Asia and North America. According to National Geographic, “The team selectively fed the insects a sugar solution colored with food dye,” meant to put a hue to their poo. Some got red, some got blue. After two months, the researchers could clearly see that the ant dung—technically called “frass”—accumulated in certain corners of their nests.
As one of the study’s lead authors, Tomer Czaczkes, puts it, “there must be a selective advantage” to the ants’ tidiness. Feces can carry bacteria, for one thing, so it makes sense that the bugs might not want it just hanging out all over their homes. But other social insects, like honeybees for example, make a point out of removing their frass from their nests altogether—so why don’t black garden ants do the same?
The cause for such storage is still unknown, but as National Geographic highlights, there are a variety of bugs and animals that use their poop for practical purposes. Termites, for example, produce waste with antimicrobial properties, which can help maintain the whole colony’s health. Researchers plan to evaluate whether ant frass may have similar powers.
But it could also be that the ants are saving up the waste to feed to their larvae. After all, what baby bug doesn’t enjoy a nice, homemade snack?