Envenomation by a Black Widow has its own name: latrodectism. The venom is a neurotoxin which is more powerful than that of a cobra snake; however, its bite injects such a small volume of venom (known as alpha-Latrotoxin) that less than one percent of Black Widow bites in humans result in death.The spiders are nonaggressive and bite only in self-defense. Black Widows spin webs that lack shape and form. Their webs are erratic in appearance, and the silk is stronger than almost all other arachnids. The webs are rough and sticky. The black widow spider is shy and nocturnal in habit, usually staying hidden in her web, hanging belly upward.