What are teeth used for?

"That's easy," you say.

"Teeth are for eating."

You're partially right.

For people, that's the purpose of teeth:

biting off and chewing food

(and occasionally ripping into that package of cookies).

For animals, teeth are good for more than just eating.

They might be used for fighting,

communicating, or even building a home.

Some animals have a continuous supply of teeth.

The shark has two sets of teeth,

so a missing tooth is automatically replaced.

Many reptiles like lizards

also have a constant supply of new teeth

replacing the old ones.

Many animals use their teeth to battle.

Walruses have two ivory teeth called tusks

that can grow up to almost a meter long.

Male walruses fight each other over females,

and the one with the longest tusks usually wins.

Elephants also have tusks,

though theirs can grow to be over three meters long!

They use them to protect mates and young,

even fending off lions if necessary.

ther animals may attack prey with their teeth.  

Alligators and crocodiles don't use their teeth to  chew,

but to seize prey, which they swallow whole.

They may lose teeth,

but backups are waiting to move up and fill the empty spots.

Some animals have sharp front teeth called  fangs,which kill.

A poisonous snake can push venom through its fangs,

leaving its victim helpless.

Vampire bats use fangs to pierce holes in their prey's fur and skin.

Then they lap up the blood (their food) with their tongues.

Hyenas' small teeth are set in powerful jaws

that can crush the bones of a much larger animal.

Some animals use their teeth to send a message.

Horses show teeth to express different feelings.

They might talk tough, welcome others, or show respect.  

Porcupines click their teeth to warn others  to stay away,

while hippos yawn to threaten.

Baboons scream and show a mouth full of huge,  pointed teeth

to both frighten intruders and make their young behave.

Angry bison grind their teeth,

making a squeaky sound. Stay away!

A few animals use their teeth to supply shelter.  

Naked mole rats use four razor-sharp teeth to  dig tunnels, which serve as a home.

(Their lips seal behind their teeth

so that soil doesn't enter their mouths.)

Their teeth are constantly growing,

but wear down as the top and bottom teeth

scrape together while digging through hard soil.

Beavers also have four front teeth that continually grow.

These teeth wear down from gnawing through trees.

After toppling a tree, beavers use their  teeth to drag logs to the water.

They use these logs to build a home, or lodge,

and also to create a dam, which protects the lodge.

Some animals also use their teeth to groom, or clean, themselves.

For example, there is a group of animals called prosimians,

which means "before the monkeys.

" They're monkey-like creatures, but they aren't monkeys.

There are about 50 animals in this group,

including lemurs, aye-ayes, and lorises.

The type of teeth and the way they use them

tell us that they must be prosimians.

Almost all prosimians have comb-like lower front teeth

that they use to clean the fur on their bodies.

So, as you can see,

teeth are not only used for eating.

They're also useful for building shelters,

digging holes, warning off predators, catching and killing prey,

fighting, and keeping clean!