American dog ticks are considered to be three host ticks because they feed on three different hosts throughout their development into larva, nymph, and adult.
The life cycle of the American dog tick begins when the adult females detach themselves from their host and land on the ground, usually under some leaves or in heavy vegetation; she will then lay up to 5,000 eggs. The six-legged larvae will emerge from those eggs and find a small mammal like a mouse to attach themselves to and feed on. The larvae will then drop off and cast-off their skin to become an eight-legged nymph. The nymph then goes on to find another small mammal to attach to and feed on. After a period of time, they will grow into an adult who will then look for a preferred large host to feed on such as: Dogs, Coyotes, Deer, Domestic cats, Livestock, & Humans.
The entire process of developing from egg to adult can take anywhere from 3 months to 2 years depending on environmental conditions.
When American dog ticks bite their hosts they can spread a variety of dangerous diseases including tularemia, a type of bacterial infection, which can lead to tick paralysis. They can also transmit Rocky Mountain spotted fever, and Colorado tick fever. When removing an attached American dog tick from you or your pet it is important to use tweezers or forceps instead of your fingers. Squeezing the body of the American dog tick can lead to its body fluids being released onto your fingers which can then be spread to your mouth, eyes or other mucous members causing the increased spread of Rocky Mountain spotted fever and other diseases.