What Is a Black Legged Tick?

The black legged tick, scientific name Ixodes scapularis, is a species of tick that lives in wooded areas in the northeastern United States, Mexico, and Canada. It is also commonly known as the deer tick. The black legged tick is perhaps most famous for spreading Lyme disease, an infectious disease caused by bacteria of the genus Borrelia. As it progresses through its two-year life cycle, the black legged tick feeds on the blood of animals and people, making it a disease hazard for hikers and others who spend time in wooded areas.

After the black legged tick hatches from its egg, it takes two years to progresses through the stages of larva and nymph to finally become an adult. Black legged ticks in the nymphal stage are only about the size of a poppy seed. Female adult ticks are about ¹/₁₀ of an inch (2 or 3 millimeters) long, while males are slightly smaller.

The female black legged tick makes three blood feedings in its life. Larval ticks may pick up Lyme disease bacteria from their first feeding on the blood of a small animal, such as a mouse. A tick in the nymphal stage can spread the disease through its second blood meal. Adult female ticks feed once again on blood, becoming engorged and then laying eggs. When adults, male ticks do not feed on blood and therefore do not spread Lyme disease at this stage.

The minute size of black legged ticks makes them difficult to see, and often the tick is not discovered until it has already bitten and fed, potentially spreading Lyme disease to its host. It is recommended that hikers check all areas of the skin regularly for ticks while in wooded areas. Black legged ticks prefer to attach in warm, moist places, for example behind the ears or at the nape of the neck. If a tick is discovered before it has attached, it can be easily removed and disposed of with no harm done.

An attached tick must be removed from the skin promptly. This is done by gripping the head of the tick as close to the skin as possible with a pair of precision tweezers. The tick should be pulled out steadily to prevent breakage and ensure complete removal. Disinfectant should be applied to the site of the bite.

Signs of Lyme disease include a characteristic ring-shaped red rash that develops around the bite wound and other symptoms such as muscle pain or dizziness. If, after a tick bite, any of these signs present themselves, it is important to see a physician immediately. Prompt removal of a tick can prevent Lyme disease from developing, as it has been found that the black legged tick does not transmit Lyme disease to its host until approximately 36 to 48 hours after attachment. Some black legged ticks are not Lyme disease carriers at all, so a bite will not always result in infection.

There are numerous steps that can be taken to prevent ticks from attaching. Frequent checks are recommended for hikers, since they help reveal ticks before they have time to attach. Ticks often crawl over shoes and up under pants and socks, so tucking pant legs into socks creates a seal that prevents ticks from entering. Staying on cleared trails and out of thick underbrush and long grass is also helpful, since ticks often cling to plants and can hitch on to hikers as they brush past.