The flea life cycle begins when the female lays eggs after feeding. Fleas can lay up to 50 eggs daily, usually on the host itself, so they can easily roll onto the ground. Because of this, areas where the host rests and sleeps become a primary habitat for eggs and developing fleas. The eggs take around two days to two weeks to hatch. Flea eggs are impervious to pesticides and treatments against them. A normal flea population comprises 50% eggs, 35% larvae, 10% pupae, and 5% adults. Larvae are blind, avoid light, pass through three larval stages, and take a week to several months to develop. Fleas mature to adulthood within a silken cocoon woven by the larva to which pet hair, carpet fiber, dust, grass cuttings, and other debris adhere. In about five to fourteen days, adult fleas emerge or may remain dormant in the cocoon until movement, pressure, heat, noise, or carbon dioxide is detected. Fleas can remain dormant for up to nine months!