Tortoise, Tree Snake, Gator, and Sea Snake: What Is a Reptile?

Fossil by Fossil: Comparing Dinosaur Bones

Butterfly, Flea, Beetle, and Bee: What Is an Insect?

Save the...Whale Sharks

Salamander, Frog, and Polliwog: What Is an Amphibian?

Tooth by Tooth: Comparing Fangs, Tusks, and Chompers

Sparrow, Eagle, Penguin, and Seagull: What Is a Bird?

Baby Pandas

Dolphin, Fox, Hippo, and Ox: What Is a Mammal?

Eye by Eye: Comparing How Animals See

Marvelous Mammals

Guess What Is Growing Inside This Egg

Crow or Raven?

Crawling Cockroaches

Chipmunks