Ants, scientists have discovered, don't use an outhouse to relieve themselves but prefer the comfort and convenience of an ensuite.

After studying colonies of ants for two months, German researcher Tomer Czaczkes and his team found the tiny insects establish dedicated areas, or "toilets", to relieve themselves inside their intricate nests.

The team kept 21 colonies of black garden ants inside plaster nests, feeding them a sugar-based food laced with dye that resulted in a similar-coloured waste.

Far from being piss-ants, the coloured waste patches showed the lab specimens would only defecate in the corners of their homes.

"These patches never contained other waste material such as uneaten food items, or nestmate corpses. Such waste was collected in waste piles outside the nest," said the researchers.

"The coloured patches are best described as 'toilets'," they said.

While it would be fun to assume ant's good toilet hygiene is driven by their desire to be tidy, their behaviour has developed because it offers an advantage.

"Social insects have developed several strategies for dealing with waste and faecal matter, including dumping waste outside the nest and forming specialised waste-storage chambers," said the researchers.

One possible explanation for the ant's orderly living areas is to reduce the amount of disease-spreading bacteria. However, having toilets inside the nest may suggest pathogens aren't a big problem, said the researchers.

"In some cases waste material and faeces are put to use, either as a construction material or as a long-lasting signal, suggesting that faeces and waste may not always be dangerous," he said.

The findings have been published in the journal PLoS One.