Do prey animals e.g zebras ever sleep?
All animals have to sleep at one point or another. The mind and body cannot physically take zero rest. However, different animals sleep in different ways. For example some insects have extremely short periods of rest, so short that if you blink or do not know what you are looking at you would miss it. Other animals like aquatic mammals, and some species of fish, have the ability to shut off part of their brain at a time so they get some rest but still move enough to breathe. Kinda like human sleep walking but it is sleep swimming. With herd animals or animals that live in groups it all depends on the species. Some take turns sleeping, others sleep all at the same time but sleep light enough that it trouble comes by they can react. Some have even learned to sleep around other species that stay awake to provide a warning that something is up. Either way, all animals rest, it is just the “how” is something that is different from species to species.