DISCUSS: Animal teeth are adapted for getting and chewing food. They can also be used for other purposes, such as protection or even building their homes!
Animals that eat meat are called carnivores. They have large canine teeth to hold and tear meat. Wolves, tigers, cats, and dogs are carnivores and have lots of sharp canine teeth. They need these strong, sharp teeth for catching and holding their prey. They bite their prey and tear the meat into pieces. They do not chew their food well, swallowing it whole or in large chunks. Some fish have teeth to help them catch their prey.
Animals that eat only plants are called herbivores. A herbivore’s long front incisors have sharp edges that are good for cutting grass and leaves. They have large molars at the back of their mouths for grinding and crushing the stems, leaves, fruits, seeds, and roots of plants. Their flat molars are used for grinding the plants. The long front incisors of beavers and squirrels can break into nuts and seeds. Squirrels crack nutshells with their teeth. (Don’t you try that!) Beavers, squirrels, and other rodents have teeth that keep growing all their lives. They sharpen their teeth by gnawing as they eat. Grazing animals such as horses, cows, and sheep need their large back molars for grinding up grass and grain.
Animals that eat both plants and animals are called omnivores. They have both canines and molars. Are you a carnivore, a herbivore, or an omnivore? Animals have a much simpler diet than people do.
Animals that don’t have teeth have to use other body parts to capture and eat their food. Lizards and frogs use their tongues to snap up food. Some birds use their beaks to tear food before they swallow it. Seed-eating birds use their beaks to crush the seeds. The blue whale and the anteater have no teeth.
How do animals clean their teeth? You use a toothbrush to clean your teeth, but animals clean their teeth by chewing and gnawing.
Some animals defend themselves or their babies with their teeth. Monkeys scare enemies by baring their teeth. Teeth can also be used as weapons against enemies.
Elephant tusks are long teeth outside an elephant’s mouth. They are used for protection from enemies or digging for water. Walruses use their tusks to dig up shellfish from the floor of the ocean.
A snake has two hollow teeth called fangs in its upper jaw. When a snake bites its prey, poison can squirt through small tips in the fangs.
Some animals use their teeth for building. A beaver’s incisors can cut through a tree trunk! The beaver uses the tree trunks for building a dam in the river. The beaver’s teeth wear down, but they keep on growing so they are always sharp. Some animals also use their teeth for digging or making tunnels.
Sharks have several rows of teeth. They grow out of the shark’s skin and are not anchored in the jaw. When a shark’s front teeth wear away or fall out, the teeth in the second row move forward. Sharks replace their teeth as long as they live. Other animals like dogs and cats have two sets of teeth, like people do.
- Activity: (for lower primary) Teeth or no teeth? Use a T-chart to classify animals (Student Handout 6).
- Activity: (for upper primary) The teeth of animals are adapted to eat plants, meat, or both plants and meat. Classify animals according to what they eat. Use the chart on Student Handout 7.
- Activity: Research how birds manage to grind their food. Since birds do not have teeth to chew their food, how is their food digested? (Hint: What is a gizzard, and what role do stones play in the digestion?)
- Activity: You have about 20 teeth. Your teacher and other adults have about 30 teeth. Compare that number with dogs, which have 40 teeth. Alligators have about 70 teeth. Some toothed whales have more than 200 teeth. Sharks have thousands of teeth in their lifetime. A tiger shark sheds more than 2,000 teeth every year! The giant anteater has no teeth. It crushes the ants it eats on rough lumps on the roof of its mouth. Birds, lizards, and frogs don’t have teeth. Birds use their beaks to tear or crack food before they swallow it. Using Student Handout 4, create a bar graph showing the number of teeth of a bird, a primary student, an adult person, a dog, and an alligator.
- Activity: Choose an animal that has teeth. Research to find out
- Where does your animal live? What is its habitat?
- How many teeth does the animal have?
- What does your animal eat? Is your animal a herbivore, a carnivore, or an omnivore?
- How are your animals’ teeth adapted to getting and eating its food?
- Activity: Create an animal! What is your animal’s name? Decide what your animal will look like, where it will live, and what it will eat. Think about the kind of teeth it will need to get and eat its food. Draw a picture of your animal in its habitat getting and eating food.