Echindas or spiny ant eaters as they are sometimes known are familiar to most Australians. Echidnas are monotremes (mammals that lay eggs). There are only three species of monotreme in the world. The echidna is shy and moves slowly and carefully, but can usually be approached by treading softly. It is solitary for most of the year but at mating time several males may follow a female. The echidna is adapted for very rapid digging, having short limbs and powerful claws. The claws on the hind feet are elongated and curve backwards; to enable cleaning and grooming between the spines.