How can you tell if an ant is sleepy? they can’t blink. Solution? Look at their antennae:
Diagram from a scientific paper on sleep in Solenopsis invicta showing three alert antennae positions: each with the scape, or base of the antennae forward of the eye. And two positions for deep sleep (folded in) and dozing RAM sleep (Rapid Antennae Movement) From Cassill 2009 in the Journal of Insect Behavior
Queens sleep much more than workers. Ants tend to sleep for only a few min. but they take 100s of naps each day.
One day I was returning one of my majors to her colony and she fell asleep on my hand next to my ring:
Go here to see a video of her waking up. I think she forgot where she was.