The platypus typically lays one to three eggs at one time. After mating, it builds a nesting chamber before it is ready to lay the eggs.
When the platypus is ready to lay eggs, it will build a mud block to keep predators out of its den while it lays the eggs and incubates them. This takes place a few weeks after mating. Like chickens and other birds, the platypus keeps its eggs warm for about 10 days until they hatch. After the chicks hatch, it feeds them until they are about 3 months old. Their diet consists of the mother's milk secreted through the stomach until they can go on their own to find a variety of food sources.