Fleas do play dead. Sometimes, to escape danger, a flea will lie completely still on its side with legs pulled in close to its body.
Fleas may pretend to be dead when they’re disturbed. A flea showing this behavior will lie on its side and pull its legs in close to its body. The change from rapid movement to complete immobility confuses the provoker, thus allowing the flea to escape danger.
Feigning death was first seen with human fleas (P. irritans), but was later observed in many other species.
Resuscitation from Drowning
Pet owners sometimes assume fleas quickly drown. For instance, when an animal is bathed. However, fleas easily survive being submerged in water for short periods of time. They’ll only die after 24 hours of constant submersion. Up to this point, they’ll resuscitate after being removed from the water. The fleas may look dead, but they’ll begin moving again when dry.