Black Widow

Black Widow Spiders are about 0.5 inches long, 1.5 inches when the legs are spread. They have a shiny, globular abdomen and are black and sometimes brown. Females usually have a reddish hourglass shape on the underside of their abdomen. Some species have a series of red spots and two crosswise bars on the underbelly. Males are about half the female's size, with smaller bodies and longer legs. Males usually have yellow and red bands and spots over the back, as do the immature stages. Newly hatched spiderlings are predominately white or yellowish-white, gradually acquiring more black and varying amounts of red and white with each molt. Juveniles of both sexes resemble the male and are harmless to humans. Source: Wikipedia.com