The Flea Life Cycle
Fleas have complex life cycles and pass through several stages of development as they mature from egg to adult. A female flea will lay up to 20 eggs at a time, which hatch alter several days to a couple of weeks. The larvae that emerge continue to grow and molt a couple of times over the next two weeks to six months.
Alter the final molt, the larvae spin cocoons around themselves in which they metamorphose into adult fleas. If necessary, the cocoon can protect the flea for many months, but at just the right time-usually determined by temperature and physical pressure or motion – the flea emerges from the cocoon, ready to jump on your cat or you. It then feeds on the blood of its host.
Warmth (temperatures between 60°F and 90°F or 15°C and 32°C) and relative humidity (between 65 and 85 percent) favor the flea life cycle; warm, humid areas such as the southern United States are notorious for the severity of their flea problem.