When you google it, all the first few responses say "Nope. You're a dork. Bees go to their hives at night.
But! There have been tons of bees sleeping in my flowers at night. I swear it! How else do you think I got this close to this guy?
Or this one?
I finally found one person that says "Why yes, good observation. Bees do fall asleep in flowers."
Apparently they bite a stem and hang on with their jaws for the night.
Sometimes they have slumber parties.
You can see their little abdomens inhaling, exhaling, inhaling, exhaling.
And look! Something else I hadn't realized - their antennae are knobbed.
I gotta tell you my favorite bees are definitely sleeping bees.