Echidnas: Tachyglossidae

Echidnas are monotremes, their only living relative being the platypus, and the three species together are the only living, egg-laying mammals. The mother echidna bears a single, small egg with a leathery shell that she tucks into a temporary pouch, where the offspring will hatch and nurse itself on milk excreted through pores (but no nipples) in the mother's skin within the pouch.

If threatened, an echidna has several options for defense. It can run, climb a tree, or swim. Echidnas do these things quite well. It can wedge itself into a small cranny between rocks, anchoring itself with its paws and spines. If in the open, the echidna can dig itself a hole well within a minute, burying itself, leaving some of the spines on its back poking above the soil as a final barrier.