Chicago (CBS) — The oldest animal at Brookfield Zoo, Adelaide the short-beaked echidna, turned 50 years old Saturday.

(Credit: Chicago Zoological Society)

Echidnas are native to Australia as well as Central and South New Guinea. They are only one of two mammals to lay eggs.

In celebration of her big day, Adelaide ate a cake topped with one of her favorite foods — wax worms.

(Credit: Chicago Zoological Society)