Once on a host, adult cat fleas take a blood meal and mate. Within 36 to 48 hours, the female begins laying eggs. Flea eggs are pearly white, oval with rounded ends and approximately 0.5 mm long. Eggs typically make up 50% of an infestation in the home. The female flea lays her eggs in the haircoat of the host. Since the eggs are not sticky, they fall off the host into the environment. Thus, flea eggs may be deposited in all those places to which the dog or cat has access. Female fleas can lay from 20 to 50 eggs a day and up to 2000 eggs during their lifetime. Eggs usually hatch in 1 to 10 days, depending on temperature and humidity. Humidities below 50% and over 92% kill flea eggs.