Scientists know very little about spider venom. Among all spiders, poisonous spiders are the smallest in number. Many of the Mygalomorph family possess dangerous poison. Poisonous spiders kill by injecting their prey with venom that could paralyze or kill. Poisonous spiders live all over the world.
Poisonous spiders possess poison to kill their prey.
These spiders breathe air. When a water spider web has few air bubbles, the spider surfaces, and catches air bubbles on its hairs, then swims back to its web to release them. If a spider loses a leg, it's just a matter of time until it grows another leg. Some water spiders can walk on water without sinking. These spiders capture insects and eat them in the water.