Why Tick Identification Matters
Understanding the different types of ticks can help you assess your risk of Lyme disease and
other tick-borne illnesses. Not all ticks carry the same diseases, and knowing which species
you've encountered can guide your next steps.
Common Tick Species in the United States
Black-legged Tick (Deer Tick) - Ixodes scapularis
Primary Lyme Disease Vector
This is the main tick responsible for transmitting Lyme disease in the northeastern and
north-central United States.
- Size: Adults are about the size of a sesame seed (2-3mm)
- Color: Dark brown to black with reddish-brown legs
- Habitat: Wooded areas, tall grass, leaf litter
- Geographic range: Northeastern, mid-Atlantic, and north-central states
- Diseases transmitted: Lyme disease, anaplasmosis, babesiosis
Western Black-legged Tick - Ixodes pacificus
West Coast Lyme Vector
The primary vector for Lyme disease on the Pacific coast of the United States.
- Size: Similar to the black-legged tick
- Color: Dark brown with reddish-brown legs
- Habitat: Coastal areas, wooded regions
- Geographic range: Pacific coast states
- Diseases transmitted: Lyme disease, anaplasmosis
American Dog Tick - Dermacentor variabilis
Low Lyme Risk
This tick rarely transmits Lyme disease but can carry other serious illnesses.
- Size: Larger than black-legged ticks (3-5mm when engorged)
- Color: Brown with white or gray markings
- Habitat: Grassy areas, along trails, in fields
- Geographic range: Eastern United States
- Diseases transmitted: Rocky Mountain spotted fever, tularemia
Lone Star Tick - Amblyomma americanum
Emerging Threat
This aggressive tick is expanding its range and can transmit several diseases.
- Size: Medium-sized (3-4mm)
- Color: Brown with a distinctive white spot on females
- Habitat: Wooded areas, brush, tall grass
- Geographic range: Southeastern and eastern United States
- Diseases transmitted: Ehrlichiosis, tularemia, STARI
Life Stages of Ticks
Understanding tick life stages is important for identification and risk assessment:
Larva (Seed Ticks)
- Very small (less than 1mm)
- Six legs
- Usually light in color
- Less likely to transmit disease
Nymph
- Small (1-2mm)
- Eight legs
- Most dangerous stage for Lyme disease transmission
- Hard to spot due to small size
Adult
- Larger and easier to spot
- Eight legs
- Females can become quite large when engorged
- More likely to be found and removed quickly
How to Identify a Tick
When you find a tick, look for these key characteristics:
- Body shape: Oval or teardrop-shaped
- Legs: Eight legs (six in larvae)
- Color: Varies by species and life stage
- Size: Ranges from pinhead to pea-sized when engorged
- Movement: Crawls slowly, doesn't jump or fly
Important Reminder
If you find a tick attached to your skin, remove it promptly using fine-tipped tweezers.
Grasp the tick as close to the skin as possible and pull upward with steady pressure.
Clean the bite area with soap and water or rubbing alcohol.
When to Seek Professional Help
Consider consulting a healthcare provider if:
- You're unable to remove the tick completely
- The tick was attached for more than 36 hours
- You develop symptoms within 3-30 days of the bite
- You're unsure about the type of tick
- You're in a high-risk area for Lyme disease