Some mammals may not experience vivid colorful dreams like humans do. Living in the water makes both sleeping and dreaming a challenge. First, no one is sure why we, or any other animal, dream.

Mammals are familiar beasts. From a squirrel on a power line to a blue whale swimming through the sea, we share the world with more than 6,000 mammal species of all shapes and sizes. While we can ...

All mammals have hair, but sometimes they've evolved to appear naked. Cetaceans are the largest group of hairless mammals, made up of animals including whales, dolphins, and porpoises. This makes ...

Many mammals are true hibernators and remain dormant through the winter, but a lot of them stay active, at least to some degree. Sign in or Subscribe See Offers. Sign In: Login.

Some mammals, though, would take this extra nutrition up a cup size. Over time, ancestors of marsupials, like kangaroos, and placentals, like us, evolved nipples to make delivering milk a bit more ...

First, no one is sure why we, or any other animal, dream. During the past century, however, scientists have made significant progress in understanding the factors that influence sleep and dreaming ...