Sugar ant pee preference may reduce greenhouse gases

Research from the University of South Australia has revealed that the sugar ant’s preference for urine over sugar may play a role in reducing greenhouse gas emissions.

Led by wildlife ecologist Associate Professor Topa Petit, the team observed that sugar ants nocturnally forage on urine to extract nitrogen molecules, some of which could end up in the greenhouse gas nitrous oxide.

The study compared the behaviours of sugar ants (Camponotus terebrans) as they were exposed to different concentrations of urine (human and kangaroo ~2.5% urea), sugar water (20% and 40%) and urea in water (at 2.5%, 3.5%, 7% and 10%), finding that the ants were most attracted to higher concentrations of urea, mining them for long periods within a dry sand substrate.

Assoc Prof Petit said the discovery could play a role in nitrogen cycling.

“We found that the ants determinedly mined urea patches night after night, with greater numbers of ants drawn to higher urea concentrations,” she said.

“Camponotus terebrans are undoubtedly looking for urea in urine because, similar to certain other ant species, a bacterium in their digestive tract allows them to process urea to get nitrogen for protein.

“This remarkable ability to extract urea from dry sand not only shows how sugar ants can survive in arid conditions, but also how they might reduce the release of ammonia from urine, which leads to the production of nitrous oxide — a highly active greenhouse gas.”

Nitrous oxide is 300 times more potent than carbon dioxide. Its presence in the atmosphere has increased substantially over the past decade, accelerated mostly by the widespread use of fertilisers.

“Researchers working on ants as bioindicators on grazed and ungrazed lands should take ants’ ability to process urea into account, because large amounts of urine will probably affect the assortment of ant species in the area. It would also be interesting to investigate how much ants may modify the urine ammonia volatilises from paddocks,” Assoc Prof Petit said.

Image courtesy of University of South Australia