#Crypto Female widow spiders are typically dark brown or a shiny black in color when they are full grown, usually exhibiting a red or orange hourglass on the ventral surface (underside) of the abdomen; some may have a pair of red spots or have no marking at all. The male widow spiders often exhibit various red or red and white markings on the dorsal surface (upper side) of the abdomen, ranging from a single stripe to bars or spots. Females of a few species are paler brown and some have no bright markings. The bodies of black widow spiders range from 3–10 millimeters0.12–0.39 in) in size; some females can measure 13 millimeters (0.51 in) in their body length