From resting sac of penultimate female Phidippus audax . From resting sac of penultimate female Phidippus audax . The spacing of claw teeth allows this spider to walk securely upon silk fibers. Note that one claw of each pair has approximately twice as many teeth as the other claw. The functional significance of this is not known.
Silk is as critical to the success of salticid spiders as it is to other spiders.
Phidippus routinely lay down draglines as they travel, stopping frequently to secure an attachment disk or anchor to the substrate. Before a Phidippus jumps, it lays down an attachment disk. If the jump is missed, the spider can climb back to its original position by reeling in the dragline with its first two pairs of legs. If the jump hits a prey target, the spider can hang from the dragline, suspended in the air, thus not allowing the prey to secure a foothold for leverage until it has been immobilized by injected venom. Phidippus also brakes on the dragline during a jump, to limit the distance traversed and to support the rapid and inertial flexion of outstretched legs around the targeted prey.