During this extreme warfare, thousands of worker bees from both sides perish, and young from the losing side are dragged out of the nest to die—a previously unseen behavior described in the December issue of the American Naturalist.

These battles decimate the ranks of worker bees, the sterile females that hives rely on to collect nectar and farmers use to pollinate their crops.

What’s more, they’re the only ones waging war—male drones sit on the sidelines. The battles also leave entire colonies vulnerable to parasites and disease as they settle into their newly conquered nest.

Of course, fights within and between bee species are nothing new. Robber bees in South America, for instance, make their living raiding other colonies’ food stores, Christoph Grüter, a bee biologist at the University of Lausanne in Switzerland, said via email. Nest takeovers can also occur.

Australia’s stingless bees, however, take the fighting to a whole new level, which has puzzled scientists: Why risk so many of your workers in months of fighting?

“The scale of the fighting reported by Cunningham is remarkable,” said Grüter, who was not involved in the new research.

“It’s a very risky strategy to attack another colony, and there should be some mechanisms in place that help attacking colonies choose a weak adversary,” he explained.

“But it’s completely unknown how colonies select their victims.”.. see more

source: national geographic news