(a) Echidna and Platypus lay eggs but are warm-blooded and feed their young ones with milk.
(b) Crocodile is cold-blooded reptile.
© To make the body light for flight.
(a) Echidna and Platypus lay eggs but are warm-blooded and feed their young ones with milk.
(b) Crocodile is cold-blooded reptile.
© To make the body light for flight.