• Female black widow spiders are much bigger than the males. Even so, they are quiet small. Female black widow spiders grow to about one-half inch long. They have shiny black bodies, and no hair. Young females sometimes have a row of small red spots along their backs. The most common black widow spiders are called Latrodectus Mactans. These females have red hourglass-shaped markings on the undersides of their bodies.
• Male black widow spiders are very small and quite harmless. They are usually less than one-third the size of the females, which makes them only about one-sixth of an inch long. Male black widows also have black, shiny bodies, but do not have any red markings like the females. Unlike the bite of a female, the male black widow spiders’ bite is not at all dangerous to humans.
• Female black widow spiders live much longer than the males. A female sometimes lives as long as 18 months, but a male’s life span is only from 25 to 40 days. Black widow spiders shed their skin in order to grow. This is called molting. Female black widows molt seven to nine times before reaching maturity. Males only molt between four and seven times.
• Scientists think that female black widows only have babies once in their lives. They lay their eggs in the early spring, in round cocoons about one-half inch across. Each cocoon contains between 250 and 750 eggs. The female spider guards her cocoons very closely. After about thirty days the black widow spiderlings hatch from the many eggs.

Common name: Black Widow
Kingdom:  Animalia
Phylum: Arthropoda
Class: Arachnida
Order: Araneae
Family: Theridiidae
Genus: Latrodectuc
Species:  There are 31 different species

• Black widow spiders belong to the Theridiidae family of spiders. People used to think that the female black widow spider always ate the male, making herself a widow. This is how the black widow spider got its name. In fact, she does sometimes eat both her mate and spiderlings, but this is quite normal for many female spiders.
• Black widow spiders are found in countries with fairly warm climates. They live in the warmer parts of North America and in Mexico. In Australia, they are called “redbacks,” and in New Zealand, they are called “katipos.” Black widow spiders also live in the warm countries surrounding the Mediterranean Sea. There are four species of black widow spiders in the United States.