Researchers from the University of Regensburg gave ants housed in plaster nests either blue or red water to color their faeces, which helped the scientists keep track of who was dropping what where.
The published findings showed that ants designate fixed corners exclusively for relieving themselves inside the nest.
However, before anyone puts the “ant”, in “anthromorphize”, it isn't quite clear that ants employ toilets for the same hygiene-related reasons humans do.
Rather, the scientific team composed of Tomer J. Czaczkes, Jürgen Heinze and Joachim Ruth say the ants may be keeping the toilets as repositories to keep their faeces for further use.
They noted ants kept their toilets inside, rather than outside their nests, and did not remove their droppings along with their other waste such as uneaten food or dead comrades – leaving the researchers to speculate on the possible benefits of keeping the waste in close quarters.
“Why faeces is not removed with other waste materials is unclear,” the scientists wrote in the abstract.
“The presence of the toilets inside the nest suggests that they may not be an important source of pathogens, and may have a beneficial role.”
The scientists theorised unused nutrients in adult ant droppings may be used to feed young larvae. After having observed the growth of “fungus-like fruiting bodies” on the toilet patches, the research team has said it is also possible the ants are using the toilets as a sort of garden, eating the fruiting bodies as a way to absorb otherwise inaccessible nutrients.
The scientists describe the study as "first step" in understanding ant toilets in nests.