Question: what is the difference between a hedgehog and an echidna?
Answer: Hedgehogs are placental mammals; echidnas are monotremes. Hedgehogs and echidnas both have spines. ... Hedgehogs have teeth; echidnas do not. Hedgehogs have 3 to 4 young, after a gestation period of 35 to 58 days; echidnas lay one egg 22 days after mating, which they tuck in their pouch.