A spider has four pairs of legs, which are attached to its cephalothorax. Each leg has seven segments. In most kinds of spiders, the last segment has two or three claws at the tip. A pad of hairs called a scopula may surround the claws. The scopula helps the spider cling to such surfaces as ceilings or walls.

When a spider walks, the first and third leg on one side of its body move with the second and fourth leg on the other side. Muscles in the legs make the legs bend at the joints. But spiders have no muscles to extend their legs. The presure of the blood in their bodies makes their legs extend.

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This page was last updated on 10/27/2009.