The Black Widow spider is the most poisonous spider in North America, but only the adult female. Black widow spiders are found in the warm, dry parts of the world and prefer to spin their webs in dark, sheltered spots close to the ground. Although the spider is mostly found in the southern United States, it may be seen throughout the US.
Bites in humans
The black widow spider has a potent neurotoxic venom and is considered the most venomous spider in North America. However, the female injects such a small dose of venom that it rarely causes death. Reports indicate human mortality at well less than 1% from black widow spider bites.
Reaction to a black widow spider bite, depends entirely on the area of the body bitten, amount of venom injected, and their sensitivity to the venom. The venom of a black widow spider is particularly dangerous, because one cannot feel the bite when it occurs, and when the person discovers it, it is can already be infected. At first, there may be slight local swelling and two faint red spots, which are puncture points from the fangs. Pain soon begins and usually progresses from the bite site to finally localize in the abdomen and back.