Spitting Spider

Summary: Spitting spiders are known for their ability to spit a venomous silk from their fangs that immobilizes their prey.

If ever there was to be a cartoon, the spitting spider should be the model. Imagine a spider that can spit a gummy substance to plaster its prey against a wall. Wiley Coyote needs this trick to capture the evasive roadrunner.

Spitting spiders are small, measuring less than a quarter inch in length and they are slow, too. So, what's a tiny, slow spider to do? He spits, of course. Most spiders have silk glands in their abdomen. They use the gland to make silk that is used to build webs and to protect their egg cases. Spitting spiders also have a silk gland, but they use their silk glands to spit silk from large

credit: M. Schmitt

holes in their small fangs enabling them to capture prey much larger than itself. The tiny spiders can spit silk a maximum of 60mm or over two inches. This is ten times the length of their body. The spit covers the victim in about 1/600th of a second. I said they moved slowly, but they spit faster than a speeding bullet.

Spitting spider web in flight

Spitting spiders vary in color by species, but the most commonly found spitting spider in the USA inhabits New Mexico. It is yellow with black spots on its back like a panther, and black rings around its legs. The spider is not dangerous to humans because its jaws are too small to bite through our skin.

Most spitting spiders are not social and will spit on each other until one or the other is immobilized. Then, of course, it's lunchtime. But, one group of spitting spiders in Madagascar is known to be a social spider. They live in small groups, building webs in trees, using sticky silk to weave together groups of leaves. The social behavior is very rare in spiders. For the spitting spiders, this social behavior probably benefits them in two ways. Building larger nests help them to capture more prey, and when they attack prey that is too large for one spider to handle on its own, the other spiders in the colony can help out by adding their own sticky, silk streams of spit to the capture effort.