Animal Groups
Browse animals by group: mammals, birds, reptiles, amphibians, fish, insects, arachnids, crustaceans, mollusks and other invertebrates.
- Mammals Warm-blooded animals with hair or fur that feed their young on milk, from tiny shrews and bats to elephants and blue whales. 187 articles
- Birds Feathered, egg-laying animals with beaks and wings, from hummingbirds and owls to eagles, penguins and ostriches. 115 articles
- Reptiles Scaly, cold-blooded animals that rely on outside heat to stay warm: snakes, lizards, turtles, tortoises and crocodilians. 80 articles
- Amphibians Animals that usually start life in water and later live on land, with moist skin: frogs, toads, salamanders and newts. 20 articles
- Fish Animals that live in water and breathe with gills, from sharks and rays to salmon, seahorses and clownfish. 36 articles
- Insects Six-legged animals with three body parts, the most diverse animal group on Earth: bees, butterflies, beetles, ants and dragonflies. 37 articles
- Arachnids Eight-legged animals without antennae, including spiders, scorpions and harvestmen. 20 articles
- Crustaceans Mostly aquatic animals with a hard outer shell and jointed legs: crabs, lobsters, shrimp, krill and woodlice. 8 articles
- Mollusks Soft-bodied animals, many with shells: snails, slugs, clams, octopuses, squid and the nautilus. 15 articles
- Other Invertebrates Animals without backbones that are not insects, arachnids, crustaceans or mollusks: jellyfish, corals, sea stars, worms and centipedes. 16 articles