To warn potential predators, the most toxic amphibians are also the most brightly colored. Curare [kyoo-RAW-ree], for example, is found on the skin of colorful poison dart frogs. Another special ...

Vertebrates, for example, are divided into mammals, birds, reptiles, amphibians and fish. Mammals are warm-blooded animals with hair or fur and can produce milk to feed their young. They have ...