Sound and Animals

Lesson Plan - Get It!

Audio:

The Science of Sound

Sound is energy that travels in waves. These waves move through air, water, or even solid objects.

When they reach an ear—or another special body part—they make tiny parts vibrate. Those vibrations are sent to the brain and translated into sound.

Humans use eardrums and inner ear hairs to do this. But animals? They have an incredible variety of ways to “hear” the world.

Bats: Night Flyers With Built-in Radar

Most bats can’t see well in the dark, so they use echolocation (also called biosonar).

A bat makes high-pitched squeaks that bounce off objects and return as echoes. From the echo’s speed and shape, the bat can tell if it’s flying near a tree, another bat, or a tasty insect.

Bats can hear sounds up to 110,000 Hz—far higher than humans, who max out around 20,000 Hz.

Fun fact: Bats roost under bridges, but they don’t hunt there. Car noise doesn’t throw them off because their high-pitched echolocation is different from low car rumbles. They leave their roosts at night to hunt in the open air.

Dolphins: Underwater Whistlers

Dolphins are masters of sound beneath the waves. They send out clicks that travel through water, bounce off fish or rocks, and return to them.

With this sonar, dolphins can “see” even in murky water. They can hear up to 120,000 Hz—six times higher than humans.

Dolphins also use whistles to talk to each other, almost like names. Each dolphin has its own unique whistle, which works like an underwater signature.

Snakes: Listening With Their Jaws

Snakes don’t have ears sticking out of their heads. Instead, they sense sound through their jaws and bones.

When sound vibrations move through the ground or air, the snake’s body feels them and passes them along to the inner ear. This lets snakes “hear” low rumbles and vibrations that help them find prey or escape danger.

Spiders: Hair-Raising Hearing

Jumping spiders have no ears at all, but they don’t need them. Their legs are covered in super-sensitive hairs that can pick up vibrations in the air.

Scientists once thought spiders could only detect very close sounds, but new research shows they can “hear” from over 10 feet away!

When they sense a low-frequency sound, they often freeze, a survival trick to avoid predators like wasps. In other words, a spider on the wall may know you’re clapping across the room.

The Big Picture

Every animal has its own way of using sound.

Bats and dolphins use echoes to see the invisible. Snakes sense rumbles through their bones. Spiders detect air vibrations through hairs. Humans rely on eardrums.

However, in the end, all hearing comes down to vibrations.

Now that you’ve explored how animals hear, it’s your turn to put this knowledge to the test. In the Got It? section, you’ll practice and compare what you’ve learned about the amazing, sometimes surprising ways animals use sound.