The amazing puggle
Baby echidnas are called puggles. They start life when the mother lays an egg about 22 days after mating.
Getting an echidna egg from the cloaca to the pouch, is not an easy feat and no-one's actually seen it happen. However Penny Rismiller has occasionally seen echidnas sitting upright on their tails without any support for their backs, while they use their snouts to groom their belly fur. She says that in this sitting position a female echidna's cloaca could extend to reach into the folds of the pouch.
Once in the pouch it's 10 days before the baby echidna hatches. Only 1.5 centimeters long, its hind legs are just buds, but the front legs already have tiny claws that can hold onto the mother's pouch hair. The egg is usually in the far end of the pouch and so the tiny echidna must travel around six times its own body length to get its first drink of milk.
The milk comes from two 'milk patches' located on each side of the front end of the pouch where a nipple would normally be found. Echidnas don't have teats for the hatchlings to attach to.
Young puggles grow incredibly fast. They can increase their weight six hundredfold, from three to 180 grams in 60 days. The mothers spend a lot of time foraging for food to keep up the milk supply.