What is the plural of platypus?
Answer. The plural of platypus is platypuses. Like most other nouns that end in –s, it takes –es to form the plural.
Do any mammals lay eggs?
Mammals. As for us mammals, only two types lay eggs: the duck-billed platypus and the echidna. After a three-week pregnancy, the short-beaked echidna of Australia makes a nursery burrow, where she lays her egg directly into her pouch, incubating it for ten days until it hatches into a baby.