This was the scene a couple of evenings ago in our front yard, a slumber party for the Yellow-Faced Bumble Bees Bombus vosnesenskii !
In the photo above one of the bees squeezed into a partially closed California poppy, to settle in for the night.
Its leg, with a full pollen basket, seems to be draped over the side of a petal.
This bee is sleeping on a lambs ear flower spike, on an area which is soft and fuzzy.
The antennae are drooping over the bee's face.
Since bees don't have eyelids, the only way you can tell that they are sleeping is when they remain completely still on a plant.
In the past I have seen honeybees that were completely still, but that was because a crab spider had attacked and killed them on the face of a sunflower.
Another bee was sleeping on the flower cluster of a nude buckwheat plant.
The cluster is still in bud phase, so I wonder how this bee got a good grip on the buds.
The next morning all the sleeping bees were up and about by eight o'clock, buzzing around the garden.