Pet Armor For Cats (3 Month) PetArmor contains fipronil, so it kills fleas and ticks on your pet. Any flea larvae in your home may hatch and appear as adult fleas on your pet. PetArmor will kill stragglers too, so your pet will be protected for a full 30 days. EPA Reg No. 86230-1-85495. EPA Est. No. 2517-NE-02