Figure 7: Nest closing and reopening. (a) Closing of an entrance hole from the inside of the nest by an egg-laying female; the sealing itself took 8 seconds while the whole closing activity continued over a further five minutes; images a1 to a6 were taken every seconds. (b) Opening of the nest entrance by circling movements by a worker bee from outside. This process took 8 minutes. The nest entrance was closed up at 11:20 h; at 11:28 h the worker bee in the image reopened the nest from outside. Four minutes later, the entrance hole was closed again. The images b1 to b6 were taken in the last minute before the forager bee succeeded to enter the nest.