When a nursing baby short-beaked echidna begins to grow spines, it leaves its mother’s pouch.It comes back to nurse at her milk patches for several months. Native to Tasmania and New Guinea, echidnas are monotremes unlike most other mammals, monotremes never evolved live birth, but instead lay eggs like their amniote ancestors. Monotremes produce milk for their young. But they lack nipples; instead, their milk oozes out of ducts of their mammary glands onto specialized patches of skin.