Facts about spider you probably didn't know.

The bite of the Brazilian wandering spider can cause long and painful erections, as well as other symptoms, in human males.

Spiders have blue blood. In humans, oxygen is bound to hemoglobin, a molecule that contains iron and gives blood its red color. In spiders, oxygen is bound to hemocyanin, a molecule that contains copper rather than iron.

The most deadly spiders in the world include the black widow, funnel web, and brown recluse spiders. One of the most feared spiders in the world, the tarantula, actually has surprisingly weak venom and a bite that feels more like a wasp sting.

The word “spider” comes from the Old English word spithra and is related to the German spinne, both of which mean “spinner.” The word “spinster” is also related and means “one who spins thread.”

Hummingbirds use small sticks and the silk from spider webs to weave a nest for themselves.

The bird-dropping spider gets its name because it looks like bird poo. This type of camouflage prevents birds from eating it.

Hundreds of years ago, people put spider webs on their wounds because they believed it would help stop the bleeding. Scientists now know that the silk contains vitamin K, which helps reduce bleeding.

Spiders are blamed for all kinds of bumps, rashes, and growths. However, unlike mosquitoes or ticks, spiders don’t feed on human blood and they have no reason to bite a human unless they feel threatened or surprised. Additionally, spiders do not typically bite sleeping humans.