Cats have three kinds of sleep: the brief nap, the longer
light sleep, and the deep sleep. The brief nap is the one
we call a "catnap". The light sleep and the longer sleep
alternate during those periods of time when a cat settles
down for something more than a catnap. When a cat is ready
for some sleep, it begins in a phase of light sleep that
lasts for about half an hour. Then, the cat enters the
period of deep sleep, which lasts for 6 or 7 minutes.
After this, the cat will return to light sleep and
alternate these two phases until he or she wakes up.
During deep sleep a cat will dream, with twitchings and
quivering of the ears, paws, and tail. The mouth may make
some sucking movement. There may be some vocalizations --
growls, purrs, and other sounds. There are also bursts of
rapid eye movement during the deep sleep.
A kitten, during the first month, experiences only deep
sleep, which lasts for about 12 hours total each day.
After the first month, the kitten quickly switches to
the adult pattern of sleep.
Cats are super-sleepers, sleeping about 16 hours a day
total. Most mammals do not sleep this much, which puts
the cat into a special category -- that of the efficient
hunter. The cat is so efficient at obtaining food, that
it has time to spare, so it has time for more sleep.
Other carnivores, like dogs, have to spend much more time
running around, searching and chasing, to obtain their
food. But the cat sits, waits, stalks a little, kills,
and eats. That done, the cat grooms and takes a nap. Our
housecats have even less to do, and they don't have to
fit more activities into their day, so they can still be
super-sleepers.
