At the end of the pregnancy the expectant mother takes up a sitting position and grooms her pouch. The baby emerges from an opening at the base of her tail called the cloaca. The infant is very tiny, only about the size of a lima bean. It’s pink and largely undeveloped except for its two front arms that are crucial for its climb up its mother’s abdomen to the pouch. The baby, which is little more than a fetus, makes this climb completely unaided and guided only by instinct. Once inside the pouch the baby finds one of its mother’s four nipples and takes the end of one in its mouth. The baby doesn’t have the muscles to suck at this stage. Instead, the nipple swells inside the baby’s mouth so that it can’t disengage and milk is secreted very slowly into its mouth. Later, once the baby’s jaw is more developed, it will be able to disengage and suck at will.