Yes, platypuses are one of the few mammals that lay eggs. They are part of a group known as monotremes, which also includes echidnas. Monotremes are unique in that they reproduce by laying eggs rather than giving birth to live young. Female platypuses typically lay one to three eggs in a nesting burrow, where they incubate them until they hatch. The eggs are leathery, not hard like bird eggs, and the female curls her body around them to keep them warm during the incubation period, which lasts about ten days. After hatching, the mother nurses her young with milk produced by mammary glands, as platypuses do not have teats.