The black widow received its name because it was believed that females would eat males after mating, but actually, this is very rare. In most cases, males are able to escape without harm after mating.
A male black widow will recognize a female because of the pheromones in her web. He will enter the web and begin rearranging it while vibrating his abdomen to get the female's attention. This technique puts her in a trance-like state, and the male will attempt to mate. If he is unsuccessful, he will go back to rearranging the web and try again.
In a rare case, if the female does choose to attack, the male is most vulnerable during the mating phase because he has to remove his pedipalps from the female before attempting to escape.