Echidnas are toothless and feed almost exclusively on ants and termites. They expose termite galleries by breaking open nests with their strong forepaws or snout or by digging into soil. They then extract the termites, which adhere to their long, sticky tongues. When disturbed, the echidna either curls into a spiny ball to protect its soft underside, or digs its belly into the soil, so that only the spines are exposed.
Long spines cover the body and fur is present between them. These slow-moving creatures have a bulbous forehead and a long snout to collect their food. Males have a spur on the ankle of the hind leg but, unlike that of the platypus, it is not venomous. They are equipped with a long sticky tongue that extends perhaps 17 centimetres beyond the end of the snout.
This unusual mammal lays eggs and suckles its young. The echidna does not have teats, the baby clings to specialised hairs within the pouch, where it suckles milk oozing from the mother's mammary glands.