Crab spiders have crablike moves and powerful venom:
Crab spiders articulate backward, forward, and sideways movements with the fluidity of crabs. They belong to the Thomisidae spider family whose species total 2,000 worldwide and 200+ within North America. They can be recognized by:
• two backward-curved humps of four feeble-sighted, small-sized, wide-spaced eyes each, atop the cephalo-thorax (merged head and thorax);
• two front pairs of long, seven-segmented, slim legs capable of pincer-snapping prey, covered with prey-immobilizing hairs on the insides, and culminating in two-clawed tips; and
• two rear pairs of seven-segmented, short, stump-like legs ending in two-clawed tips.
Since they do not have teeth with which to mash such food sources as insects, especially ants and bumblebees, and other spiders, they depend upon fangs.