Tarantulas reproduce sexually through the joining of sperm and egg. Males transfer sperm to their pedipalps prior to mating. As is the case in most species of spiders, male tarantulas are smaller than females, making copulation dangerous for them.
Male tarantulas are sexually mature after their final molt. Males wander in search of a female and mating takes place near her burrow or shelter. When the male locates a female he spins a sperm web where he deposits his sperm before transferring it to his pedipalps. The male and female tarantulas face each other and the male uses his tibial spurs, small hooks on his first pair of legs, to hold the larger female's jaws in place and away from him. He then uses his pedipalps to deposit sperm in the female's reproductive organs on the underside of her abdomen. Male tarantulas leave the female's territory soon after mating to avoid being killed or eaten. In the wild, tarantulas often mate in summer or early fall but the female stores the sperm in her body until spring. The female spins a special web and deposits eggs onto it before introducing sperm. Once fertilization occurs, she wraps the eggs in a sac and carries it with her fangs until the eggs hatch one to three months later.