Each person needs a different amount of sleep, and these needs change throughout the lifecycle. Most adults need 7-8 hours of sleep each night.

Newborns, on the other hand, sleep between 16 and 18 hours a day, and children in preschool sleep between 10 and 12 hours a day. School-aged children and teens need at least 9 hours of sleep a night.

Cats seem to need about 27 hours of sleep a day and 45 seconds of psychosis 3 to 4 times a day.