What is the life span of fleas?

30-90 Days (Average). A flea might live a year and a half under ideal conditions. These include the right temperature, food supply, and humidity. Generally speaking, though, an adult flea only lives for 2 or 3 months. Without a host for food, a flea's life might be as short as a few days. But with ample food supply, the adult flea will often live up to 100 days.