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.
Some people call orcas the wolves of the sea, yet others want to swim with them. Why are these animals known as killers -- or are they just getting a bad rap?
Environmentalists agree that beaver dams help the environment by creating wetlands but why are some landowners and farm owners getting riled up? How could these dams be hazardous to roads, bridges and levees?
If your favorite diner's blue plate special is ever sauteed polar bear liver, you may want to stick with salad. This meal can cause symptoms far beyond indigestion.
Bushy mustaches like the ones that Magnum P.I. or Super Mario sport are a bold fashion statement. But for baleen whales, they never go out of style.
If you've seen Disney's "The Lion King" or HowStuffWorks's "Meerkat Manor," you're familiar with the celebrity meerkats. And whether your favorite is the animated Timon or one of the reality TV families, it's hard not to fall for these small mammals.
Tigers, the largest members of the cat family, live in the forests, savannas and swamps in Asia. See pictures of these great feline carnivores, including the Bengal tiger, Sumatran tiger and more.
She's a vicious social climber, willing to do anything to get to the top. In her quest to be queen, she's snubbed girls and stolen their men. Oh, yes -- and she's a meerkat.
Young meerkat pups pass their days in the Kalahari Desert by playing. But it's not all fun and games: Playtime makes them vulnerable to predators. So why persist?
When it comes to lending a helping paw, meerkats are quite altruistic. Strangely, they evolved from the mongoose -- a real loner. What gives?
Mealtime in the Kalahari Desert isn't exactly an all-you-can-eat buffet. Meerkats eat what they can get -- even poisonous scorpions. Why doesn't the venom hurt them?
From sonnets to Skype, humans have been perfecting communication for centuries. Meerkats have their own ways of pointing out danger, food and even happiness.
You're probably familiar with celebrity meerkats like the Whiskers clan and Timon. But do you know anything else about this creature from the Kalahari?
Did you know that there are 37 species of dolphin? This dolphin image gallery depicts and handful of these species, including the bottlenose, dusty, false killer whale dolphin and more.
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?
The polar bear's shocking whiteness, ferocity and sheer size make it an icon of purity and power. How do these animals survive in a frigid climate?
If you want to determine whether you've got your hands on a wallaby or a kangaroo, you're going to have to pry open the animal's mouth and examine its molars.
Each year, thousands of male Pacific walruses pack the beaches of Round Island off the coast of Alaska. Is there a reason for this months-long male bonding?
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.
Fainting goats don't really faint -- their muscles tense up and they fall over when they get scared. But why would anyone want a fainting goat?
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.
Until now, no one has documented a definite case of chimpanzees using tools to hunt in the traditional sense. Find out what a new study on chimpanzees may reveal about human evolution.
Did you know you conserve energy every time you walk across a room? You do, in evolutionary terms at least. Find out how and why humans began walking upright and what this has to do with our body's energy use.
Cow flatulence produces the greenhouse gas methane, which is linked to global warming. Find out how scientists are working to reduce cow flatulence in livestock.