Kid Questions: Do Frogs Have Lips?

by Deb on November 7, 2011


The quick answer is ‘no,’ frogs don’t have lips. They have some very interesting features in their mouths, but lips like we have belong to monkeys, apes and us.

Primate lips

There are 5 types of large animals we’re most familiar with – fish, amphibians, reptiles, birds and mammals. Mammals have very different mouths to the others because we drink milk as babies. This means our mouths are developed for sucking and we have cheeks that can move and lips that can close around the nipple and help us suck.

Most mammals have thin lips that are attached to their gums, but for monkeys, apes and us our lips are free. This lets us have expressive faces and communicate in our social groups. Apes are the most like us, and chimps even kiss each other.


Photo courtesy of Thomas Lersch

We have very big lips, they are extremely important in communicating. Smiling in happiness, laughing and talking are all uniquely human and all use our lips. The reason they look red is they have very thin skin like the inside of our mouths and you can see the blood underneath.

Frog lips

frog mouth

You can see that there is a border around a frog mouth, but it isn’t plump red lips like ours. It opens so wide because there are no cheeks and inside is very different to ours too.

Starting at the top there are nostrils inside the mouth as well as outside. These are to help the frog breathe. Frogs use their lungs when they are out of the water, but they can also dissolve oxygen in a thin layer of water on their skin and absorb it straight into their blood.

There are two types of teeth in the top jaw – there are small teeth around the edge and two larger teeth called the vomerine teeth just inside the nostrils. But there are no teeth on the bottom jaw. This means frogs can’t chew their food, the tiny teeth are only used for holding it before they swallow.

Moving down are two big round things that are actually the bottom of the eyes! The top of your mouth has a layer of bone, but frogs just have skin and their large eyes are right on top of their mouth. In fact, frogs use their eyes to swallow their food. They push their eyes down and it pushes their food back into their throat. There is a video at the bottom that shows the frog’s eyes pushing in as it swallows.

Right at the back are the openings of the eustachian tubes, these drain the ears and ours go into our noses. In the middle is the throat. Then on either side are the openings of the vocal sac, which is how male frogs sing.

vocal sac

Photo courtesy of Christian Fischer

The tongue is the opposite of ours, it is attached near the front and curls back into the mouth. This lets it shoot out to catch unsuspecting prey.

Have a look at this video, the interesting part is around 2 minutes. The frog catches the fish and then pushes his eyes down to swallow them.

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{ 2 comments… read them below or add one }

Mummy Crit via Facebook November 7, 2011 at 2:21 pm

Fantastic!! We particularly liked the bit about frogs using their eyes to swallow, and that frogs can “use their tongues like hands” Thankyou!


Tracy November 25, 2011 at 10:01 am

Shared this one wih my 4 yr old and he loved finding out that frog use their eyes to help them swallow! Thanks!


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