Its habitat includes wooded areas, abandoned fields, medium height grasses and shrubs between wetlands and woods, and sunny or open areas around woods. The adult American dog tick feeds on a wide variety of medium to large size mammals, such as dogs, cattle, deer, raccoons, and opossum.
All stages of the American dog tick will also feed on humans if given the opportunity.

The American dog tick is a three-host tick - each development stage feeds on a different host.
The female feeds for 7 to 10 days, drops to the ground, and after several days lays 4,000 - 6,500 ellipsoidal eggs over a 14 - 32 day period and then dies.

This species is the most common vector of Rocky Mountain spotted fever (RMSF), which the tick can transmit after only 5-20 hours of feeding. It can also transmit Tularemia (hunter's disease).
Apparently, it plays no significant role in the transmission of Lyme disease and Babesiosis.

PDF (155 kb): The veterinary Clinics of North America, p. 45-46