What Do Ticks Look Like?
Most ticks that people come into contact with are hard ticks that have a hardened, shield on their backs called the scutum and their mouthparts are visible when viewed from above the tick. The other tick group is soft ticks. Their appearance is much different than the hard ticks. Soft ticks have a leathery body, are more oblong and “fatter” than hard ticks, and their mouthparts are not visible when viewed from above. A simple description of soft ticks is they look like a small, symmetrical bean with legs. Soft ticks are not as frequently encountered by people because they live in rodent burrows, caves and in hidden away, protective places that bats and rodents inhabit.
Hard ticks go through four life stages during their life cycle: eggs, larvae (six-legged), nymphs (eight-legged) and adults (eight-legged). While there is “no ONE SIZE FITS ALL” description, adults are about ¼-3/8 inch long (about the size of a freckle). Tick nymphs are about the size of the head of a pin and the larvae are about the size of a poppy seed. The tick consists of two parts: a head and an abdomen. The tick’s head is very small compared to its abdomen, so much so that oftentimes they are described as looking like a body with six or eight curved legs. The tick’s two pair of front legs curve toward the head, while the two sets of hind legs curve toward the abdomen.
Generally, male ticks are smaller than the females.
Both male and female ticks consume a blood meal. When ticks are engorged with blood from their host, they increase in size as they consume more blood. When fully-engorged, hard ticks typically increase in size to become close to twice the size of an unfed tick adult. An engorged female hard tick may appear swollen, grayish-colored and about the size of a small to medium sized lima bean. Tick abundance varies by location and environmental conditions; however, generally the most abundant ticks are the blacklegged ticks, the lone star ticks and the American dog ticks.
BLACKLEGGED TICK (Ixodes scapularis) & THE WESTERN BLACKLEGGED TICK (Ixodes pacificus)
Deer ticks are the transmitters of Lyme disease. They are very small and are somewhat smaller than most other species of hard ticks. In fact, the larval and nymph stages are so small, they are often overlooked when attached to a person or their pets. Both species have a reddish-orange colored abdomen and their scutum is black or dark brown. Their legs are black or dark colored which is why they have the common name blacklegged ticks. Unfed adult females are about 1/8 inch long, but expand to about 3/8 inch long when fully engorged. Ixodes pacificus distribution is the Pacific coast north through British Columbia and east into Nevada, Utah and Idaho while Ixodes scapularis distribution is the northeastern and upper Midwestern portions of the United States.
LONE STAR TICK (Amblyomma americanum)
Lone star ticks are one of the more easily recognized ticks since the female adult has an easily noticed white dot on the center her back. Adult males have white lines or streaks around the edges of the top of their body, but not the white dot of the female. Adult females that are not blood engorged are about 3/16 inches long. Once the female feeds on a host, their shape is more circular and about 7/16 inches long. Unfed males are slightly smaller than unfed females. The larva is very tiny, only a little larger than a poppy seed. The nymph is the most common stage found on people and is about the size of a pinhead. This tick is distributed in the southeastern and eastern United States.
AMERICAN DOG TICK (Dermacentor variabilis)
The American dog tick is dark brown with whitish markings on its back and is one of the larger species of ticks found in the United States. However, the larvae and nymphs are very small and are not easily seen. The adult female is 3/16 inch long before feeding, and when engorged with blood, can be up to 5/8 of an inch long and 3/8 of an inch wide. Engorged females look like dark pinto beans. Male ticks do not change notably in size as they feed. This tick is widely distributed east of the Rocky Mountains and in limited areas along the Pacific coast.