Ticks belong to a group of organisms that also includes spiders and scorpions, called arachnids. Ticks are ectoparasites, or parasites that live outside of an animal’s body. They feed on the blood of the host animal and can transmit diseases from a previous host organism while they are feeding. Ticks are responsible for the transmission of a variety of diseases, including lyme disease, Rocky Mountain spotted fever and tularemia. Most tick-borne diseases are caused by the transmission of bacteria through the tick’s saliva, but there are some diseases that are caused by protozoans or viruses.
There are at least 800 different known species of ticks worldwide. The numerous species can be classified into two main different types of ticks, known as soft ticks or hard ticks. The Ixodidae, or hard ticks, have a hard protective shell, called a scutum, on their back. The hard ticks take longer to feed, usually several hours to complete a feeding. They also do not transmit disease as quickly as soft ticks, because transmission is more likely to occur at the end of a feeding period rather than the beginning. The soft ticks, known as the Argasidae, do not have a hard back. These ticks also have a shorter feeding time which is usually completed in less than an hour. They are more likely to transmit a disease at the beginning of a feeding period.
Ticks become more numerous during the spring, summer and early fall. Many ticks die during the winter, but winters that are not as harsh can lead to greater numbers of ticks the following spring. To reproduce, ticks lay eggs in the vegetation that hatch into small 6-legged tick larvae, sometimes called “seed ticks.” These larvae can already feed on a host. As the ticks grow, they will molt into an 8-legged nymph, or juvenile tick. A second molt will complete the tick’s maturation into an adult tick.
Ticks find their hosts by sitting on tall grasses or shrubs and crawling onto passing animals. They do not jump or fly. Even though many ticks, like the deer tick or dog tick, are named after their preferred host species, most ticks will feed on the blood of any mammal they encounter. Humans walking in the woods can be bitten by ticks that do not normally use humans as their typical host. Ticks usually secrete chemicals that reduce pain and inflammation when they bite so that the host is less likely to feel the bite and notice the tick while it is feeding. This makes it more likely that a tick will be able to complete a feeding without being disturbed.
Thank you for visiting pain.com, your pain management resource!