From dogs that doze off and on, to dolphins that sleep using only half their brains, here’s a look at the many ways animals sleep
all also build sleeping platforms in trees, away from predators and insects, a jungle version of a bed. Gorillas sleep for 12 hours but orangutans get around the same eight hours that humans do.
The reason great apes have such long, luxurious sleep compared to the fitful, shorter sleeps of their monkey cousins has to do with those sleeping platforms. Monkeys have to balance on hard branches where they are easily awakened by potential danger or other monkeys—which is helpful to them but not good for extended sleep.
showed that orangutans do, indeed, sleep better than their baboon cousins. The apes’ cognitive abilities, the study says, may improve on the day following that longer, deeper sleep.Dolphins, meanwhile, can stay alert with half of their brain while the other half can fall into a deep sleep. This enables dolphins to sleep with one eye open, looking for predators.