Bees Can Count

Honeybees are clever little creatures. They can form abstract concepts, such as symmetry versus asymmetry, and they use symbolic language — the celebrated waggle dance — to direct their hivemates to flower patches. New reports suggest that they can also communicate across species, and can count — up to a point.

With colleagues, Songkun Su of Zhejiang University in Hangzhou, China, and Shaowu Zhang of the Australian National University in Canberra managed to overcome the apian impulse to kill intruders and cultivated the first mixed-species colonies, made up of European honeybees, Apis mellifera, and Asiatic honeybees, A. cerana. The researchers confirmed that the two species have their own dialects: foraging in identical environments, the bees signaled the distance to a food source with dances of different durations.

Remarkably, despite the communication barrier, A. cerana decoded A. mellifera's dance and found the food.

Also at the Australian National University, Marie Dacke and Mandyam V. Srinivasan trained European honeybees to pass a particular number of colored stripes in a tunnel to get a food reward, which was placed by a stripe. When they removed the food, the bees still returned to the same stripe.

Next, they mixed things up on the bees: they varied the spacing of the stripes, and even replaced stripes with unfamiliar markers. The insects consistently passed the same number of markers to approach the former reward site, demonstrating that they could count, up to four.

The studies burnish the impressive list of honeybees' known cognitive abilities, all achieved with a brain the size of a sand grain.

The studies were detailed in the journals PLoS One and Animal Cognition.