tick

Ticks are small parasitic arachnids that belong to the sub class Acari and the order Ixodida. They are ectoparasites of vertebrates, feeding on the blood of mammals, birds, reptiles, and amphibians. Ticks can transmit a variety of pathogens, making them significant in human and veterinary health.

There are two main families: hard ticks (Ixodidae) and soft ticks (Argasidae). Hard ticks have a hardened shield called a scutum and a visible capitulum (head) at the front; soft ticks have a leathery body and their mouthparts are less conspicuous. Adults range in size from a few millimeters to over a centimeter when engorged.

Ticks have a four-stage life cycle: egg, larva (six legs), nymph (eight legs), and adult (eight legs). All active stages require a blood meal from a host to molt or reproduce. Most species feed on more than one host during their life cycle, and feedings can take minutes to several days.

Ticks inhabit moist, vegetated environments that host vertebrates, including forests, grasslands, and shrublands. They reach hosts by questing, extending their front legs onto passing animals or people. Humidity supports tick survival; dry conditions reduce activity.

Tick-borne diseases include Lyme disease (Borrelia burgdorferi), Rocky Mountain spotted fever (Rickettsia rickettsii), anaplasmosis, babesiosis, and others. Transmission often requires attachment for several hours or days. Early removal reduces risk, but pathogens may be transmitted after a shorter time in some species.

Prevention focuses on personal protection (long clothing, repellents such as DEET or permethrin-treated clothing), regular tick checks, prompt removal of attached ticks, and habitat management to reduce tick density. In some settings, acaricides and wildlife control are used as part of integrated strategies.