Field Guide / Ticks, Spiders & Biting Pests
Blacklegged Tick
Ixodes scapularis
Also called: deer tick, bear tick
A tiny tick of eastern woods and brush, the main carrier of Lyme disease in the eastern United States, and easy to miss because the young ones are poppy-seed small.
- Kind
- Ticks
- Size
- Nymph about a poppy seed; adult about a sesame seed
- Range
- The eastern and upper Midwest states, with a western relative along the Pacific Coast
- Regions
- Northeast, Southeast, Midwest & Plains
- When active
- Adults in fall and early spring; nymphs from late spring through summer
- Concern
- Can carry disease
How to identify it
- Adults are small, with a plain dark brown or black shield behind the head and no pale markings.
- Females have a reddish-orange body behind the shield; males are mostly dark.
- The legs are dark, which is where the common name comes from.
- A nymph is about the size of a poppy seed and often goes unnoticed.
Health risk
Blacklegged ticks can spread Lyme disease, anaplasmosis, babesiosis, and Powassan virus. The risk is highest in the Northeast and upper Midwest. Nymphs cause many cases because they are so small and active in spring and summer.
How to avoid it
- Treat boots, pants, socks, and gear with 0.5% permethrin, or buy pre-treated clothing. Do not put permethrin on skin.
- Use an EPA-registered repellent on exposed skin, such as DEET, picaridin, IR3535, or oil of lemon eucalyptus, and follow the label.
- Walk in the center of trails, and avoid brushing against tall grass and leaf litter when you can.
- Do a full tick check after being outdoors: under the arms, in and around the ears, inside the belly button, behind the knees, in and around the hair, between the legs, and around the waist.
- Shower within two hours of coming indoors, and tumble dry clothes on high heat for 10 minutes to kill ticks. Check pets and gear too.
If you find a tick on you
- Use clean, fine-tipped tweezers to grasp the tick as close to the skin's surface as you can.
- Pull upward with steady, even pressure. Do not twist or jerk, which can leave mouthparts in the skin. If some stay behind, remove them with the tweezers if you can, and otherwise leave them alone and let the skin heal.
- Clean the bite and your hands with rubbing alcohol or soap and water.
- Do not crush the tick. Dispose of it by putting it in alcohol, sealing it in a bag or container, wrapping it tightly in tape, or flushing it down the toilet.
- Do not use folk remedies such as nail polish, petroleum jelly, or a hot match to make the tick let go.
When to get medical care
- See a doctor if you get a fever, chills, a rash (including a spreading or bull's-eye rash), a severe headache, or muscle and joint aches in the days to weeks after a tick bite.
- Tell the doctor you were bitten by a tick, where you were, and about when it happened.
- Get care if you cannot remove the tick, or if the bite looks infected.
Call 911 for trouble breathing, swelling of the face or throat, a racing heart, dizziness, or fainting.
Often confused with
- American Dog Tick: larger, with pale cream markings on the shield.
- Lone Star Tick: the adult female has a single white spot on her back.
Field notes
Blacklegged ticks live in leaf litter and low brush and climb onto passing animals and people. They do not jump or fly. Along the Pacific Coast a closely related species, the western blacklegged tick, plays a similar role.
Related guides
This page is general information from public health sources such as the CDC, not medical advice. Risks vary with where you live, your health, and any allergies, so talk to a doctor or pharmacist about repellents, allergy plans, and vaccines. Follow the label on any repellent or insecticide.