If one pet in the household has fleas, will the others get them?

Generally, the answer to that is yes. Fleas don't discriminate, so you want to make sure that all your pets are protected.

Yes, fleas can easily spread to other pets in the household. When one pet has fleas, the fleas lay eggs in the environment, which then develop into larvae, cocoons, and eventually new baby fleas. The life cycle takes about three weeks, and the baby fleas will jump onto other pet family members, causing an infestation in the home and on other pets. To prevent this, it's recommended that all dogs and cats in the household be on some type of flea prevention.