Black widow spiders are so named because of the widespread belief that the female spider always eats her partner after sex, but the mating habits of these arachnids aren’t actually so black and white.
The common name “black widow spider” most often refers to any of the three North American spider species with the distinctive dark body and red hourglass pattern. The name is also occasionally used to describe other — or even all — members of the Latrodectus (widow spider) genus, including the notoriously cannibalistic Australian redback. Despite the blanket name, the penchant for sexual cannibalism of the genus varies between species, said Chad Johnson, a widow spider expert at Arizona State University.
In each widow species, the male is no more than half the size of the female. After maturing, the male will spin a small “sperm web.” He deposits some semen into the web and coats his palps —two appendages near the mouth, which resemble tiny claws or thick antennae — with sperm. He then sets off to find a female of his species. [Gallery: Spooky Spiders]