A cat's claws are protractile.

Movements of intracellular particles along the lamellipodium formed by the foraminiferum Allogromia laticollaris.

Has humanity ever been put to a viler use than by the Banians of Surat, who support a hospital for vermin in that city, and regale the souls of their friends who are undergoing penance in the shape of fleas, or in loathsome pedicular form, by hiring beggars to go in among them, and afford them pasture for the night!

Paw-prints in the snow allow us to presume a visit from next door's cat.