SLEEP ALL NIGHT

How long animals sleep?

• Animals need diffeent amounts of sleep a day, ranging from 2 hours a day for elephants to 20 hours for dolphines
• Generally, as body size increases the required sleeping time decreases
• Among the family of cats and dog, domestic cats and dogs do not make their sleep as a single session. They spread their daily requirements of sleep fairly evenly throughout the day
• Water mammals “sleep” with alternate hemispheres of their brains asleep and the other awake, usually having one eye open to alert them if needed
• They alo do this so they can breathe above water while asleep
• Migratory birds also seem to sleep while flying

Do insects sleep?

• Fish and fruit flies appear to have a “sleeplike” state 
• “Basic Rest and Activity Cycle”, or BRAC, is a term describing alternation of the sleeplike state and its absence in animals
• However, if сparrow and fruit flies are prevented from having a restt rest, they have what is referred to as a “rest rebound” and ould die

Hibernation

• Many animals hibernate in a deep sleeplike state during winter (when available food is limited), as well as to conserve body heat and energy
• Opposite to hybernationn is Estivation, which is a similar state when some animals hibernate to escape summer heat

Do Animal Dream?

• Cattle, horses, and sheep are unique because they can sleep while standing, however for cattle and sheep, REM sleep will not occur in such a position
• For REM sleep, which is cnsidered to be a dreaming state, to take place, the animals must lie down
• From another hand, birds have periods of REM sleep while perched

How Animals Sleep? See images below and enjoy! You should be able to recognize them easily:

 Last update Oct 3, 2009