Scientifically-speaking there are 11 mammal groups, and most Mammals are warm-blooded, have body hair, give live birth and nurse their young with milk from mammary glands. Check out these articles about all kinds of mammals.
Leopard Seals Are Apex Predators of the Antarctic
With Fewer Than 10 Left, Can the Vaquita Be Saved?
Humpback Whales Have Made an Amazing Comeback From Extinction
Baby Bats Babble With Moms, Hinting at Human Language Development
Fruit Bats Are the Best Pollinators (and Suppliers of Tequila)
Brazilian Free-tailed Bats Are Way Faster Than We Thought
Alaska's Kodiak Bear Is One of the Planet's Biggest
What's the Difference Between a Brown Bear and a Black Bear?
How Polar Bears Work
Gray Wolves Will Get Federal Protection Again in Much of U.S.
The Serval Stands Tall and Jumps Like A Champion
Are Dingoes Dangerous (and Did One Really Eat a Baby)?
Dik-dik: The Tiny Antelope With the Embarrassing Name
Are Mules, Burros and Jackasses All Donkeys?
Tapir: The Ancient Fruitarian With the Tiny Trunk
What's It Like Inside a Kangaroo's Pouch?
Do Kangaroos Really Box?
The Smiley Quokka Is an Australian Super Survivor
The Tarsier Is One Weird Primate, and Yes, We're Related
Marmosets Are Tiny, Upper Canopy-dwelling Monkeys
Why Do Gorillas Beat Their Chests?
How Long Do Squirrels Live?
'Splooting': It's What All the Cool Squirrels Are Doing This Summer
Squirrels Get Jacked During Hibernation; No Weights Needed!
World's Largest Wolves by Weight: The Mighty and the At-Risk
The Pink Fairy Armadillo Is as Mystifying as Its Name
The Coatimundi Is Cute But Doesn't Make a Good Pet
Learn More / Page 12
I've heard that the black and white stripes on a zebra provide camouflage. How can this be if they're not in a black-and-white environment?
Since 1990, there have been only five panda cubs born in the United States. This may seem a little low. Getting pandas to mate in captivity is extremely difficult. Why is the birth rate for giant pandas so low? Find out the answer in this article.
Contrary to popular belief, bats don't go around biting people and sucking blood. Bats got a bad reputation from the Dracula stories, but they actually prefer eating insects over blood. Find 13 incredible bat facts only at HowStuffWorks.
Bats are often found sleeping upside down during the day. They roost in secluded areas such as hollowed out trees and caves. Have you ever wondered why bats sleep upside down? Find out the answer to this question in this HowStuffWorks article.
Monkeys and apes have lots of similarities, but they're not the same animal. In a lot of ways, it all comes down to the tail.
If you're wandering on the beach and happen upon a large mass of some sort of waxy substance, take a closer look. It could be the rare "floating gold" of the sea: ambergris. Find out whether this whale poop can help you retire rich.
Despite their monumental proportions, the most phenomenal thing about whales isn't how big they are: It's the way they live. Whales are mammals -- warm-blooded, air-breathing creatures -- but they spend their entire life in the ocean. Find out about these awe-inspiring creatures.
By Tom Harris
Do whales and dolphins sleep? I know they have to come to the surface of the water periodically to breathe, so wouldn't they die if they dozed off?