Figure 3

Design of the experimental nests. For each encounter, a guard patrolling at the entrance of the nest is trapped into the exit box of its colony. The exit box is then gently transferred into the laboratory. One experimental bee is then introduced in the box in which it is allowed to habituate to the device for 30 s. Tests begin after the microscope slide in the middle of the box is removed and the first interaction between the bees occur. Encounters are video-recorded and last five min. The letters D indicate the positions of the microscope slides allowing to close/open the different parts of the exit box.