Both species are covered with coarse hair and their backs have spines. Their snouts are elongated and slender. They have strong limbs that make them powerful diggers. Echidnas have no teeth and have a weak jaw so they feed by using their long sticky tongue to sweep up termites, ants and other small arthropods and crush these between their tongue and the roof of their mouth.
The long-beaked echidna ("Zaglossus bruiini") is the larger of two with shorter and fewer spines. It lives in forest of New Guinea.