Teeth and Tusks

Animals use their teeth mainly for eating. Yet, animals primarily thought of as predators—such as lions, wolves, and other large carnivores—have sharp teeth and fangs for killing prey and shearing meat from bones. These predators usually have strong jaws, too. A hyena’s jaws can crush the leg bone of a zebra. Smaller predators use their sharp teeth to kill prey.

The sharp tusks of a hippopotamus can be used as a weapon. Here, a hippo marks its territory by opening its mouth—a behavior seen mainly during mating season.

Plant-eating animals, or herbivores, have teeth adapted for feeding on plants. Horses’ teeth push up slowly out of their jawbones during their entire lives. This is to replace the top parts that wear down from grazing. A deer has nipping teeth in the front of its lower jaw and a tough pad on the top jaw, which it uses to rip leaves off plants. Molars in the back are used for chewing. Rodents have front teeth that grow continuously throughout their lives. Elephants have several sets of teeth, with new sets moving in from the back to replace worn-out ones in front.

Teeth also make good weapons. Many animals, such as lions, tigers, dogs, bears, and badgers, show their teeth and growl if threatened. Some grazing animals, such as horses and zebras, bite attackers. Mice, rabbits, and other small animals also bite if they are caught.

Animals with special long teeth called tusks are equipped with dangerous weapons. An elephant’s two front teeth are tusks, which may stick out of the mouth. The tusks of a male African elephant can be up to 8 feet (2.4 m) long. Elephants use their tusks to dig water holes, scrape bark off trees, and spar with each other. They also use them as weapons against lions and other animals that prey on their calves.

Hippopotamuses use their long, razor-sharp lower teeth as weapons. A hippo tusk can grow up to 20 inches (51 cm) long. Males bite each other while fighting. Females use their tusks to keep males away from their babies. If a predator comes near a calf, the mother hippo will attack it, too. A hippo can kill a lion, and can even bite a crocodile in half.

Another African animal, the warthog, has four tusks. Two sharp tusks jut from the lower jaw, and two more curl from the upper jaw. Warthogs use these tusks to dig up roots to eat. Male warthogs also use the blunt, curled tusks when they fight one another. If a lion threatens a warthog, the warthog runs away or dives backward into a burrow, with its tusked snout facing outward.