Black widow spiders are arachnids that are known for the females' unique appearance and tendency to eat their mates. They are considered the most venomous spiders in North America; however, their bite is rarely fatal to humans.
Male and female black widows look very different. Female black widows are about 1.5 inches long. The males are about half the size of females. In all cases, the females are the most distinctive, with shiny black bodies and a red hourglass-shaped marking on the underside of their round abdomen. The hourglass marking can, on occasion, also be orange-yellow. Males, on the other hand, are lighter in colour, with red or pink spots on their backs.