Cat Sleep

The cat needs between 12 and 16 hours of sleep, but usually he or she sleeps more, an average of 15 to 18 hours per day. The cat is still awake about 6 to 9 hours in a day, including part of the night to hunt.

The cat is an animal with a large proportion of sleep that is REM sleep (the last stage - fifth stage - of a cycle of sleep phases) during which he or she dreams: the daily duration of this phase lasts from 180 to 200 minutes in cats, as against approximately 100 minutes for humans. That's why the cat is frequently used in experiments in respect of sleep cycles.

---

REM sleep: Rapid eye movement (REM) sleep is a normal stage of sleep characterized by rapid movements of the eyes. REM sleep is classified into two categories: tonic and phasic. It was identified and defined by Kleitman and Aserinsky in the early 1950s (src: Wikipedia)

---

During the phases of REM sleep, the electrical activity of the brain, eyes and muscles is very important. Several movements occur such as agitation of the vibrissae (whiskers), the twitching of the legs and tail , the beating of the eyelids, the change in position for example.

It should be noted that these phases of REM sleep are very important in the cat: it allows him or her to keep a balanced mind (since he/she dreams of hunting, what he does during the time he is awake). This REM sleep time may be increased by meals spread throughout the day. During the REM sleep it is likely that the cat catches imaginary prey because it is possible to observe in some individuals the movement of limbs that evoke hunting positions.

When the cat enters a phase of REM sleep, the delimitation of its encephalogram is similar to that of awakening despite a total loss of consciousness: the nervous system is probably empty, or selecting and storing the events of the day and evoking memories of past perceptions, hence the assumption that REM sleep is a witness to the dream.