Are you wondering whether any mammals lay eggs? Well, the answer is pretty simple. Only two types of mammals lay eggs: the duckbill and the spiny anteater. The duckbill also called platypus, is found in southern Australia and Tasmania. The spiny anteater, of which there are several varieties, occur in Australia, Tasmania, and New Guinea.
Duckbills lay their eggs in nests built in burrows in the banks of streams. The female probably incubates the eggs in .some fashion, but the creatures are very shy and not much is known about this part of their activities.
The female spiny anteater has a small pouch on the under the surface of her body, where the single egg is kept until it is hatched. The young anteater remains within the pouch for a time after hatching and gets milk from the teats in the walls of the pouch.