Two-way flea protection kills adult fleas and flea eggs before they hatch. Fleas are present year-round, even in colder climates. And if you see one flea, there's a good chance many more fleas, larvae and eggs are nearby. Fleas can carry diseases, transmit tapeworms and cause flea allergy dermatitis—the most common allergic skin disease of cats. If an infestation is bad enough, it can even cause anemia, which can be fatal to kittens. That's why you need Provecta for Cats.