Which animal's teeth grow continuously throughout their life?

Beavers are large, semiaquatic rodents in the genus "Castor" native to the temperate Northern Hemisphere. Beavers are the second-largest living rodents after the capybaras. They have stout bodies with large heads, long chisel-like incisors, brown or gray fur, hand-like front feet, webbed back feet and flat, scaly tails.

Beavers have long incisors that get their orange color from an iron-rich protective coating of enamel. Their teeth grow continuously throughout their life, but daily use helps trim them down.

Because the softer dentine (bony tissue that forms a tooth) wears away faster than the enamel, a beaver’s teeth wear down unevenly. This gives the incisors a chiseled shape, which helps beavers cut through hard objects like wood.