Fleas are a type of wingless parasite found worldwide. They feed off the blood of humans and animals such as dogs and cats. Diseases can be transferred from one host to another. Fleas are known to transmit tapeworm larvae. Ticks are external parasites that need a blood meal to survive and reproduce. Ticks can feed on humans and other mammals, reptiles, birds or even frogs. All life stages of ticks feed on blood. Ticks can transmit several diseases, such as Lyme disease, rocky mountain spotted fever, tick paralysis and others, but most tick bites do not result in illness.