By Jason Daley
Poison dart frogs are some of the most brilliantly colored and beautiful animals on Earth. About one-third of the 300 species of the tiny frogs in the superfamily Dendrobatoidae are poisonous, including the golden poison frog, which may be the most toxic animal in the world.
While venomous animals, like snakes, sequester their venom in glands or pouches, the frogs' poison is found in tissues throughout their bodies. Researchers have wrestled with that fact for a while: Why don't poison dart frogs poison themselves?