Like most arachnids, spiders lay eggs when reproducing their young. When the female is ready to lay her eggs, she may lay as many as 1,500 at a time, although the number depends on the size and species of spider. Generally, spiders lay as many eggs as they can because few will survive to maturity.
Spiders do not mate in a traditional manner. Instead, the male releases sperm onto a small web and then physically carries it to the female he couples with. He then places it into her genital opening, and when the female spider is ready to lay her eggs, she fertilizes them with the sperm.