Dogs and cats can be a joyful addition to the family, but when they’re outdoors they can pick up annoying pests, including fleas. While fleas are tiny insects, they can infest your precious pet and cause great annoyance. Worse, they can be brought into your home where they can get into your carpet and reproduce. Before you know it, you have a major problem with small fleas biting everyone in the family. While fleas usually cause little more annoyance to humans with tiny red bites, they can also cause allergic reactions. These reactions can include large welts and swelling that