Which animal have bones on the inside?

Animals that have bones on the inside are called vertebrates. This includes:

* Mammals: Humans, dogs, cats, whales, bats, etc.

* Birds: Chickens, eagles, penguins, etc.

* Reptiles: Snakes, lizards, turtles, crocodiles, etc.

* Amphibians: Frogs, toads, salamanders, etc.

* Fish: Sharks, goldfish, tuna, etc.

There are also some exceptions within these groups, like some snakes and lizards who have lost their limbs and their bones over time.

Let me know if you'd like more details on any of these animal groups!