Size

• Female black widow spiders grow much larger than the male of the species. In comparison to the female black widow, the male grows to one-fourth of her size. This makes eating the male after mating much easier.
  
  

Color

• A female black widow has a solid black coloring. During early stages of development, a female will have a gray or pale brown coloration. Likewise, the adult male shares the same coloration as an immature female. He typically has a brown or gray color.
  
  

Hourglass

• The most recognizable trait on a black widow is the color of the hourglass shape on the abdomen. While males may have a small hourglass, it has a yellow or orange color, whereas the female has a large, red hourglass on her abdomen.