Grouping of visual objects by honeybees.

Recent work has revealed that monkeys as well as pigeons are able to categorise complex visual objects. We show here that the ability to group similar, natural, visual images together extends to an invertebrate - the honeybee. Bees can be trained to distinguish between different types of naturally occurring scenes in a rather general way, and to group them into four distinct categories: landscapes, plant stems and two different kinds of flowers. They exhibit the same response to novel visual objects that differ greatly in their individual, low-level features, but belong to one of the four categories. We exclude the possibility that they might be using single, low-level features as a cue to categorise these natural visual images and suggest that the categorisation is based on a combination of low-level features and configurational cues.