Today’s Wonder of the Day was inspired by Kalex. Kalex Wonders, “How can you move your ears” Thanks for WONDERing with us, Kalex!
Isn’t the human ear fascinating? We think so! For such a small body part, it has so many pieces. There’s the eardrum, of course. And the ear canal. Most people know about the ear lobes. But did you know your ears also have many tiny muscles?
They do! In fact, those muscles are what help you move your ears. Wait. Can you move your ears? It’s no easy task, and some people can do it better than others. Go ahead and try it. Did you wiggle your ears a bit?
You probably even use your ear muscles sometimes without knowing it. Studies show that the muscles on and around human ears twitch in response to many things. For example, the muscles right behind your ears likely twitch when you’re surprised by a noise. In many cases, the muscles on the tops and outsides of the ear move when people shift their eyes from right to left.
Of course, even when these muscles twitch, human ears move very little or not at all. So what’s the point? What are all those little muscles supposed to do?
Well, they don’t really do much anymore. At some time in the distant past, they had a job. An ancient ancestor of modern humans may have been able to move their ears to a much greater extent. Experts say they likely moved their ears in response to sound. Doing so allowed them to pinpoint where a noise was coming from faster.
However, once human ancestors started walking upright, they relied much more on eyesight than on hearing. Very slowly, over millions of years, the tiny muscles on their ears became less and less important. Today, they still exist, but with no real purpose, much like human wisdom teeth. Experts call them vestigial, meaning they’re leftover from ear muscles that were probably much larger millions of years ago.
If you’ve spent much time around animals, you probably know many of them can move their ears much better than people can. That’s because, over all those millions of years, their ancestors relied on their sense of hearing more than humans did. This gave them ears that are easier to move and muscles capable of moving them to a greater degree.
Have you ever seen a dog perk up their ears when they hear a sound outside? How about a cat swivel their ears toward the source of a noise? Both dogs and cats have more muscles in their ears than humans do. Dogs have 18 ear muscles, while cats have over 30. As a result, they can both move their ears to hear better.
When you think of strong ears, your mind might immediately jump to rabbits. And for good reason! Rabbits can rotate their ears up to 270 degrees, allowing them to pay close attention to sounds. Yes, bunnies really do put those big ears to good use!
But perhaps the best ears in the animal kingdom belong to bats. They use echolocation and can hear almost 10 times better than humans. Of course, bats can also move their ears to better hear. Some even adjust the shape of their ears to hear better!
Of course, not all animals have stronger ears than people. In fact, some animals don’t have ears at all. If you’re not sure whether you can move your ears back and forth, there’s only one way to find out. Give it a try! You may just discover an ability you never knew you had.
Standards: NGSS.LS1.A, NGSS.LS1.D, NGSS.LS3.A, NGSS.LS4.B, CCRA.R.4, CCRA.L.3, CCRA.L.6, CCRA.R.1, CCRA.R.2, CCRA.SL.1, CCRA.SL.2, CCRA.R.10, CCRA.W.4, CCRA.W.3, CCRA.L.1, CCRA.L.2