Book 33, Question 2 · Video
Why do all mammals have three tiny bones in each ear?
Inside your ear are three bones called the hammer, anvil, and stirrup. They are the smallest bones in your body. When sound hits your eardrum, the bones pass the shaking along to the inner ear. Millions of years ago, the ancestors of mammals used some of these same bones in their jaws. Over time, they became tiny helpers for hearing.
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What Crafty Clover says in this video
Intro
Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why do all mammals have three tiny bones in each ear?
The Big Idea
Inside your ear are the tiniest bones in your body! There are three of them. Why do all mammals have them?
Three Bones
Step one: Three Bones. Inside your ear are three bones called the hammer, anvil, and stirrup. They're the smallest bones in your body.
Passing Sound
Step two: Passing Sound. When sound hits your eardrum, the bones pass the shaking along to the inner ear. Then your brain hears the sound.
Old Jaw Bones
Step three: Old Jaw Bones. Millions of years ago, the ancestors of mammals used some of these same bones in their jaws. Over time, they became tiny helpers for hearing.
A Closer Look
Let's take a closer look! First bone. Middle bone. Smallest. Starts it.
Quick Facts
Quick facts! The stirrup is about as small as a grain of rice. There are three bones in each ear. They were once jaw bones. They pass sound along.
Think Like a Scientist
Now, think like a scientist! Hold a rubber band near your ear and gently pluck it. Then rest it on a table. Put your ear on the table and tap it. Notice how vibrations travel through things. That's like the bones in your ear.
Outro
Mammals have three tiny ear bones, the hammer, anvil, and stirrup, that pass sound vibrations from the eardrum to the inner ear. Long ago, mammal ancestors used some of these bones in their jaws. Science is amazing! Keep wondering and keep exploring! Share what you learned with someone at home, and see what they think! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!