Spiders

Spiders

Spiders are arachnids, a class of arthropods that also includes scorpions, mites, and ticks. There are more than 45,000 known species of spiders, found in habitats all over the world. There’s a spider with a cartoonish butt, spiders that can jump on demand, and cannibal spiders that look like pelicans.

Spiders range in size from the tiny Samoan moss spider, which is .011 inch long, to the massive Goliath birdeater, a tarantula with a leg span of almost a foot.

Though all spiders have venom to one degree or another, only a handful are dangerous to humans. Those include the black widow and the brown recluse. The vast majority of spiders are harmless and serve a critical purpose: controlling insect populations that could otherwise devastate crops.

Most species are carnivorous, either trapping flies and other insects in their webs, or hunting them down. They can’t swallow their food as is, though—spiders inject their prey with digestive fluids, then suck out the liquefied remains.