Fleas feed on blood and will attack people and pets. They can reproduce at a rate of 40 to 50 per day for around 50 days, a single female flea can produce 2,000 eggs in her lifetime. Treating both the environment and the pet is important if you think that you have fleas on your property. Flea lava will burrow into hair and skin as well as bedding, so it is crucial you kill off the flea and the larva to achieve full eradication.