The number of spider eggs in an egg sac varies depending on the spider and can range from 10 to 1,500 or more. Some spiders produce multiple egg sacs to give more offspring a chance for survival, while others put all their eggs in one sac.
Hunting spiders typically produce fewer offspring but offer greater protection for their young. Other classes of spiders produce hundreds or thousands of eggs, expecting a percentage to survive. When the baby spiders are born, some parent spiders protect them with webbing until they are mature enough to leave, while some species carry the babies on their back during adolescence.