Sugar ants found to feast on urine

The greater the urea concentration, the more ants came - even preferring it to sugar. Photo: S Petit.
The greater the urea concentration, the more ants came - even preferring it to sugar. Photo: S Petit.

A study conducted on Kangaroo Island is attracting swarms of international attention.

Researchers at the University of South Australia and Kangaroo Island Research Station have discovered that species of sugar ants were not only attracted to urine from humans, kangaroos, and other vertebrates, but mined it from sand for up to a month.

Research in Germany had shown that certain ant species had bacteria in their digestive tract that allowed them to process urea to derive nitrogen, which is used to build protein - and more ants.

"We compared different baits with different urea concentrations until 10%, and the greater the urea concentration, the more ants came. They preferred it to sugar," lead investigator associate professor S. "Topa" Petit said.

It seems to be the case for KI residents Camponotus terebrans and Camponotus consobrinus.

The Australian researchers set out to study urine and urea exploitation by the nocturnal ant Camponotus terebrans on the Dudley Peninsula.

The mining behaviour of ants continued for a month on the most concentrated stain.

"There went my holidays," Ms Petit said.

"Night after night, the ants came back, with some also foraging during the day. I kept thinking, surely tonight it's over... but no." The ants' way of collecting the urea is still unclear, but certainly remarkable.

"This research has numerous implications," noted Ms Petit.

"First, foraging on urine allows these ants to increase the size of their ecological niche, because unlike other ants, they have access to an additional source of nitrogen on sandy soils notoriously poor in nitrogen.

"They may displace other ant species and modify ecosystems in areas with high availability of urine, for example paddocks.

"They also have a role in nitrogen cycling, with the potentially important reduction of nitrous oxide, a greenhouse gas that comes in part from ammonia released from urine.

"Although they are known as sugar ants, these ants' favourite dessert is not sugar!

"They are fiercely carnivorous too, but how gentle and attentive they look when they feed on urine. You can learn a lot by peeing in the bush."

The research article is in press in the journal Austral Ecology.