Spiders are egg-laying animals; females lay clutches of eggs in a weblike sac. These sacs can house thousands of eggs, and the female spider may simply lay and abandon her eggs, or she may stick around to protect them until they're hatched. Specific reproductive processes may vary by species, but in general, male spiders deposit a sperm web into a female spider's abdominal reproductive organ.
The reproductive process can be potentially dangerous for male spiders. Generally, female spiders are larger than their male counterparts, and they may decide to eat a prospective suitor rather than mate with him. In an attempt to avoid this grisly fate, male spiders may perform a mating dance or some other ritual to appear more appealing as a mate.
Though female spiders do eventually lay their eggs for hatching, the eggs also spend time developing in the female spider's abdomen. After the eggs are laid, they can develop for a week to several months, depending on the spider species and the time of year. Some spider species, such as the Lycosidae, carry their egg sacs around, while others simply lay them on a web or nest. After being hatched, baby spiders will molt — or shed their skins — several times as they develop. Some spider species continue to molt as adults, while others only molt during adolescence.