Deer Ticks - The most common carrier for Lyme Disease in the U.S., the deer tick in its nymph stage feeds on humans. The deer tick is principally found in the Northeast (from Maryland to Maine) and Northern Midwest (especially in Wisconsin and Minnesota), to a lesser extent in the South and along the coastal areas of California, Oregon and Washington. On the Pacific Coast, particularly in Northern California, the disease is transmitted by the western black-legged tick, and in the Southeastern states possibly by the black-legged tick.

The deer tick is also the species responsible for Human Granulocytic Ehrlichiosis and Babesiosis. Very small and hard to see, the deer tick is dark in color. Before reaching adulthood, it is as small as a poppy seed. As an adult, it is the size of a pinhead.

Rocky Mountain Wood Tick - This tick is most commonly associated with Rocky Mountain spotted fever, anaplasmosis and what is known as tick fever, is found principally in mountainous areas.

American Dog Tick - Another common vector for Rocky Mountain spotted fever, anaplasmosis and tick fever, the American dog tick in the adult stage attacks humans. It is found in all states east of the Rocky Mountains and is well established in Idaho, Washington and Oregon.

Brown Dog Tick - This most common tick in the U.S. infests human and pet habitats-which are often but not necessarily the same areas. Associated with Human Granulocytic Ehrlichiosis and tick paralysis, it only occasionally bites humans.

Lone Star Tick - Another vector of Rocky Mountain spotted fever, as well as tularemia and tick paralysis, the Lone Star tick in the adult stage will attack humans.