The American dog tick and brown dog tick are both known to infest domestic animals. Both are hard tick species and may also feed upon the blood of humans. Dog ticks are vectors of a number of diseases, including Rocky Mountain spotted fever. Like other ticks, the American dog tick begins as an egg and passes through larval and nymphal stages prior to emerging as a mature adult. American dog tick larvae and nymphs are responsible for feeding on smaller mammals, while adult specimens choose larger hosts, such as dogs and humans. The American dog tick is notorious for spreading Rocky Mountain spotted fever, a disease that causes nausea, lack of appetite, fever and muscle pain in victims. The brown dog tick is small in size and reddish brown in color. These ticks feed on a variety of mammals, but are partial to canines. These ticks are the ones most commonly found indoors. Despite this, they seldom bite humans. They, too, undergo a four-stage life cycle and feed on hosts before each moult.
While house pets bring most ticks inside, brown dog ticks alone are capable of completing their entire life cycle indoors. As such, populations multiply rapidly and may be found in a variety of locations worldwide.