About a half dozen species of ticks live in New Hampshire, including, the American dog tick, the winter tick, the brown dog tick, the woodchuck tick, the black legged, or deer tick, and a few other less common
varieties. All ticks must bite and draw blood in order to reproduce. Preferred species (vectors) include deer, moose, dogs, birds, woodchucks, mice, voles, and other animals. One contribution to the increase in ticks in New Hampshire is the growth of mice and voles in the state following the decrease in the number of foxes.
Ticks can carry a number of diseases, depending on the species of tick. Tick borne diseases include lyme disease, which is by far the most frequent in New Hampshire. Other, rare diseases include Rocky Mountain spotted fever, tularemia, tick paralysis, Powassan encephalitis, babesiosis, Colorado tick fever and ehrlichiosis. Lyme disease is only carried by the deer or black legged tick. Both black legged ticks and lyme disease are often observed in Amherst.
Ticks will not survive when the ground is dry. Increasing light penetration and air circulation at the ground will usually help to reduce the tick population. Keep lawns mowed and weeds and brush cut back to control ticks in your yard.
Use repellents, especially those containing DEET, to keep ticks away when hiking in the woods. Also, careful inspections of the body for the presence of ticks is important to control risks of tick born diseases. If ticks are removed within 24 hours, the risk of tick borne diseases, including lyme disease, is very greatly reduced.
The UNH Cooperative Extension has a good article on the Biology and Management of Ticks in New Hampshire.