While humans will soon be spring cleaning, moose clean house in the winter by getting rid of their antlers.

We found out quite a lot about the process when Gaia Restrepo asked: “Why do moose shed their antlers every year?”

Cattle, sheep, and goats keep and grow their horns, which are made of bone and keratin.

But members of the deer family—including its biggest member, the moose—annually shed their antlers, which are not fused to their skull. Only male moose have antlers, and their growth is regulated by testosterone, Kris Hundertmark, a wildlife ecologist at the University of Alaska Fairbanks, says via email. (Read how moose get so big eating plants.)

Casting off these massive structures frees moose of up to