As a night owl, I’m often reading some non-fiction or surfing the web late a night. My kids (pets) often start twitching or lightly making sounds as they sleep. Do animals dream? Here was an interesting post that discusses how “the size of an animal seems to affect the type of sleep it experiences.”
REM sleep amounts also vary across animal species, depending on the size of the animal and its level of development at birth. The size of an animal seems to affect the type of sleep it experiences—small animals tend to spend more time in REM sleep. Animals that are born in relatively helpless states, such as opossums and humans, generally have more REM sleep as newborns than animals that can hunt, eat, keep warm, and defend themselves soon after birth, for instance guinea pigs or horses. Even as animals age into adulthood, those born relatively immature continue to spend more time in REM sleep than animals that are mature at birth.
Which makes me wonder: do larger animals that are born in less helpless state engage in REM sleep in the womb?