Tick is the common name
for the small wingless arachnids that, along with mites, comprise
the order Acarina. Ticks are external parasites, living off the
blood of mammals, birds, and occasionally reptiles and amphibians.
The major families of tick include the Ixodidae or hard ticks,
which have thick outer shells made of chitin, and Argasidae or
soft ticks, which have a membraneous outer surface. Soft ticks
typically live in crevices and emerge briefly to feed, while hard
ticks will embed themselves beneath the skin of a host for long
periods of time.
Adult deer tick.Ticks
can transmit human diseases such as relapsing fever, Lyme disease,
Rocky Mountain spotted fever, tularemia, equine encephalitis and
several forms of ehrlichiosis. Additionally, they are responsible
for transmitting livestock diseases, including babesiosis and
anaplasmosis. Generally, tick-borne diseases correspond to a specific
tick-host combination, and are limited in their geographical extent.
Above Images Come From The USDA