Sorry if my answer seemed to be sharp - I did not mean for it to come across that way.I don't recall reading that bees sleep, and when asked about it my first reaction is to do a little research instead of simply replying "of course!"
A little google search will provide links to both answers.
A study that Thomas Selley was involved with is noteworthy in my opinion.
I believe there may be a number of things that rest but don't sleep.
We had a OH over winter and saw the same. Also many bees in different positions that would not move for long periods and then become active.I have opened hives before without smoking and have seen bees head first in cells. It was evident that they were not moving nor was their abdomen pulsating but yet they appeared to be alive.
published reports showing that approximately half of the bees in a colony at a given time are working while the rest are either inactive or patrolling, with a bias toward inactivity
A Self‐Organizing Model for Task Allocation via Frequent Task Quitting and Random Walks in the Honeybee
Brian R. Johnson
The accepted standard to define sleep is a pattern of coordinated changes in the EMG, EEG, and EOG. This pattern has been identified only in mammals and birds. Clearly, recording mass CNS activity in an attempt to identify patterns similar to the state-related EEG changes found in birds and mammals cannot logically be expected to produce interpretable results in invertebrates or even in vertebrates without a cortex.
In 1984, Campbell and Tobler reviewed over 100 studies in over 150 species seeking evidence for sleep from invertebrates to primates, using behavioral criteria. Using these criteria to review previous laboratory and field studies, the authors concluded that there is evidence for sleep-like states in 19 species of fish, 16 reptiles, and nine amphibians, as well as several invertebrates (****roach, bee, octopus).
Honeybees and ****roaches have been extensively studied. Both of these insects exhibited spontaneous circadian periods of inactivity that could last for hours. During the inactive periods, these insects relaxed their postures, even dropping the antennae, head and body onto the floor of the container. When stimulated during the rest state, the insects were relatively unresponsive.
Throughout evolution, serotonin appears to play a role in modulating state-related sensory input and motor activity levels. We have also seen that this neurotransmitter facilitates the acquisition of learning in invertebrate systems. Does serotonin play a conserved role in modulating sensory input to promote sleep in synchrony with circadian systems and facilitate neural plasticity by this means?
Joan C. Hendricks. 2000. The need for a simple animal model to understand sleep. Progress in Neurobiology