Frontline Plus has an insect growth regulator as well, which definitely prevents
flea eggs from hatching. The key is to use the products every 3-4 weeks
on all pets, and to treat the environment, because one flea on the pet means 100 eggs in the environment, which continuously hatch and reinfest the pets. Flea bombs are not bery helpful, because they broadcast the spray non-specifically over furniture and exposed flooring, but the fleas hide under furniture and in crevices.