Sorry BUGS, your brain isn't equipped for REM sleep, or any sleep for that matter.
As a cat owner and cat lover I can't help but be a little defensive. And I wonder: don't other pets kills wild animals, too?
Marine mammals don't sleep for a solid 8 hours a night, the way we do.
The main difference between hair and fur is where it grows, not what it's made of.
Rats have a strikingly different visual system than our own, one that is carefully attuned to their unique needs.
We can all hum the song from the "Jungle Book", but what really are the bare necessities for a big bear?
Scientists tested eighteen reindeer with light, and found that their eyes responded to both visible light and ultraviolet.
Scientists found that nearly identical genes play key roles in the formation of the eyes in mammals and fruit flies.
In mammals, the sex of a baby is determined by the chromosomes it inherits from its parents. But, the combination an animal inherits can be quite different.
Sure, there are physical differences but outside of mammals, the terms "male" and "female" take on different meanings.