Researchers at University of Pennsylvania School of Medicine say that the roundworm C. elegans, a worm often used in laboratory research, may help us to understand why animals sleep. Although it's called "lethargus," the period of lethargic behavior in the roundworm resembles sleep. The worm is unresponsive during this phase, and if denied the phase, the roundworm seems to suffer from sleep deprivation.
Additionally, in 2006 researchers at Northwestern University pinpointed a brain area in flies that is crucial to sleep. However insects aren't the only creatures that sleep.
It's For the Birds
Birds, like every other living creature, need sleep. When they're tired, after a big meal, or just because they've been awake for several hours, they tuck their head beneath their wings and nap. They move around a bit, ruffle their feathers, even talk or sing in their sleep.
And how do birds manage to sleep on those little perches without falling off? This is because of a special tendon in their legs that reaches from thigh to toe. When the bird sleeps, the knee bends, the tendon pulls tight and clasps the toes around the branch. Some birds sleep standing on one leg.
Some birds sleep in short bursts, and some, like swifts, even sleep while flying. Like people, most birds like it dark when they sleep.
Bright lights can give birds insomnia and they'll sing away at all hours.
Sleep: It's the Cat's Meow If you share living space with a cat, then you know how much these animals sleep, and how well they sleep! Nothing and nobody is more relaxed than a sleeping cat.
I've picked my orange tabby up off the bed, and he has laid there limp in my arms while I carried him into the living room and put him in the easy chair. Then, after I've made my bed, I've picked him up, still limp, and carried him back to his spot on the bed.
Cats generally sleep from twelve to sixteen hours a day. About 3.2 hours of this is R.E.M. sleep. R.E.M. or rapid eye movement sleep is dreaming sleep. During this stage of sleep the brain is the most active.
Sleep Disorders are Going to the Dogs
Dogs sleep ten or more hours a day. There is also a very good possibility that dogs do dream. Watch your pet as he sleeps on the rug. His ears may twitch. His nose, too. Sometimes his legs make running motions and his tail may wag. He emits little "woofs" or whimpers as he chases an imaginary rabbit or faces off against the Persian cat across the street.
Recent research at Stanford university proves that dogs also suffer from sleep disorders, and, in particular, narcolepsy. Researchers, led by Dr. Emmanuel Minot, have isolated the gene that causes narcolepsy in two breeds of dogs - Doberman pinschers and Labrador retrievers. However, it is believed that narcolepsy is a disorder common to many species.
Man is far from being the only animal that needs sleep. Neither is he the only animal who suffers from various sleep disorders.