Wood Tick Identification Guide
Dermacentor andersoni
The Rocky Mountain wood tick is a common pest in the western and northwestern United States and Canada. It is a primary carrier of Rocky Mountain spotted fever and Colorado tick fever, and can also cause tick paralysis through a neurotoxin in its saliva.
Taxonomy
Wood Tick Coloration
Common color patterns to help identify wood tick
Wood Tick
Seasonal Activity
When wood tick are most active throughout the year
Where Wood Tick Are Found
Hover over states to see their names. Green regions indicate where wood tick have been reported.
Wood Tick Identification Guide
Physical Characteristics
The Rocky Mountain wood tick (Dermacentor andersoni) is a hard tick found in the western United States and parts of Canada. Adults have a flat body shaped like a pear. They measure 2 to 5 millimeters when unfed. After a blood meal, females can swell to three times their size. They can reach up to 15 millimeters.
Colors differ between males and females. Females are brown to reddish brown. They have a silver or white shield behind the head. The body gets darker when full of blood. Males are smaller. They have gray and white spots across their back. Adults and nymphs have eight legs. Larvae have six legs.
You can also identify wood ticks by their festoons. These are small sections along the rear edge of the body. Wood ticks have 11 festoons. Under a microscope, plates near the rear legs help tell this species apart from other ticks. Wood ticks have 100 to 200 goblets on these plates. American dog ticks have more than 300 smaller goblets.
How to Tell Wood Ticks Apart from Other Ticks
Wood ticks look very similar to American dog ticks. Here are the key differences.
American dog tick. Found mostly in the eastern United States. Darker brown than wood ticks. Has more small goblets on the plates near the rear legs.
Deer tick. Much smaller with two colors. Has dark black legs and an orange-red body. Does not have fancy markings on the back.
Lone star tick. Females have one white spot on their back. More common in the southeastern United States.
The best way to tell wood ticks from American dog ticks is by where you find them. A tick found in Montana, Idaho, or Oregon is likely a wood tick. A tick found in Virginia, Maryland, or eastern states is likely an American dog tick.
Wood Tick Behavior and Biology
Life Cycle
Rocky Mountain wood ticks feed on three different hosts during their lives. They use a new animal at each life stage. The full cycle from egg to adult takes two to three years.
Females lay 4,000 to 6,000 eggs in leaf litter or soil after feeding. Eggs hatch into tiny larvae with six legs. Larvae climb onto plants and wait for small rodents like mice and ground squirrels. After feeding for several days, they drop off and molt. They become nymphs with eight legs.
Nymphs look for hosts like rabbits and ground squirrels. After another blood meal, they molt and become adults. Adult wood ticks prefer large animals like deer, elk, cattle, and humans. Adults can live up to 600 days without feeding while they wait for a host.
Host-Finding Behavior
Wood ticks find hosts through questing. They climb to the tips of grass blades or low plants. Then they stretch out their front legs and wait for an animal to walk by. They sense hosts through body heat, carbon dioxide from breathing, and movement.
These ticks do not jump, fly, or drop from trees. They only grab onto hosts that brush against them. Once on a host, they may crawl for hours before they find a good spot to attach and feed.
Habitat Preferences
Rocky Mountain wood ticks live in habitats that differ from eastern tick species. They prefer:
- Shrublands and sagebrush areas
- Lightly wooded areas and forest edges
- Open grasslands and meadows
- Trails and paths at subalpine elevations
- Areas with abundant deer and small mammal populations
These ticks are most common at heights between 4,000 and 10,500 feet. They do well in the dry areas of the mountain west. Deer ticks prefer humid forests.
Health Risks and Disease Spread
Rocky Mountain wood ticks can spread several diseases to people and animals. Knowing the symptoms helps you get treatment fast.
Rocky Mountain Spotted Fever (RMSF)
Rocky Mountain spotted fever happens across North America, not just in the Rockies. The wood tick is a main carrier in the western United States. Bacteria called Rickettsia rickettsii cause this disease.
Early signs show up 2 to 14 days after a tick bite. They include sudden fever, bad headache, muscle pain, nausea, and vomiting. A rash often starts on the wrists and ankles. Then it spreads to the rest of the body. Without treatment, up to 20 percent of cases can be fatal. Early treatment with antibiotics like doxycycline drops this to around 5 percent.
Colorado Tick Fever
This viral disease only happens in the Rocky Mountain region. The wood tick is the main carrier. Signs include fever, chills, headache, muscle aches, and tiredness. Most people recover in a few weeks. Some people have symptoms for several months. There is no specific treatment. Doctors focus on rest and fluids.
Tick Paralysis
Wood tick spit contains a toxin that can cause paralysis. This is more common with female ticks that have been attached for several days. Symptoms start in the legs and move up the body. They can include weakness, numbness, trouble walking, and breathing problems.
The good news is that tick paralysis goes away within 24 to 72 hours after the tick is removed. Finding and removing the tick fast is key.
Tularemia
Wood ticks can spread Francisella tularensis, the germ that causes tularemia. You can also get this disease from contact with sick animals or dirty water. Signs include fever, skin sores, swollen glands, and lung problems. Antibiotics work well when started early.
Medical Disclaimer: This content is for learning only. It is not medical advice. If you have symptoms after a tick bite, see a doctor right away.
Treatment Methods for Wood Ticks
Tick numbers peak in spring and early summer. Treatment plans focus on reducing ticks where they are most likely to meet people and pets.
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Targeted treatments: Granular and liquid products can go on the edges of yards where plants meet cleared areas. This targets zones where ticks wait for hosts.
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Yard changes: Keeping grass short, removing brush piles, and making barriers between wild areas and living spaces cuts tick habitat near homes.
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Wildlife control: Keeping deer and other animals away from yards can lower tick numbers over time.
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Personal steps: Using tick repellents, wearing long sleeves and pants, and checking for ticks after outdoor time are key prevention steps.
Prevention Tips for Homeowners
You can lower your risk of wood tick bites with these steps:
- Stay on cleared trails when hiking
- Wear light colors to spot ticks more easily
- Tuck pants into socks when walking through tall grass
- Use tick sprays with DEET, picaridin, or permethrin
- Check yourself, kids, and pets for ticks after being outside
- Shower within two hours of coming inside to wash off loose ticks
- Put clothes in the dryer on high heat for 10 minutes to kill ticks
How to Remove a Tick
If you find a tick on your body:
- Use pointed tweezers to grab the tick close to the skin
- Pull straight up with steady pressure
- Do not twist or crush the tick
- Clean the bite with soap and water or rubbing alcohol
- Save the tick in a sealed bag if you want it tested later
- Watch for symptoms over the next few weeks
References and Further Reading
Other Ticks
Explore other species in the ticks family
Commonly Confused With
Wood Tick are often mistaken for these similar pests
Where Wood Tick Are Found
Hover over states to see their names. Green regions indicate where wood tick have been reported.
Common Questions about Wood Tick
How do I identify a Rocky Mountain wood tick?
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Wood ticks are brown to reddish brown with a flat body shaped like a pear. Females have a silver or white shield on their back. Males have gray and white spots across their back. They look like American dog ticks but are often more red in color.
Where are Rocky Mountain wood ticks found?
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These ticks live mostly in the western United States from the Rocky Mountains to the Cascade Mountains. They are most common in Montana, Idaho, Oregon, Wyoming, and Colorado. They like shrubs, light woods, grasslands, and mountain trails.
What diseases do wood ticks carry?
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Wood ticks spread Rocky Mountain spotted fever, Colorado tick fever, and tularemia. They can also cause tick paralysis from a toxin in their spit. They spread diseases to cattle as well.
When are wood ticks most active?
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Adult wood ticks are most active from April through July. They come out after the snow melts in spring. They can stay active until November in some areas. Adults can live up to 600 days without eating.
What is tick paralysis from wood ticks?
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Tick paralysis happens when a female wood tick releases a toxin through her spit. It causes weakness that starts in the legs and moves up. The good news is symptoms go away within 24 to 72 hours after the tick is removed.
How long do wood ticks live?
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Wood ticks take two to three years to grow from egg to adult. Adult ticks can live up to 600 days without a blood meal. This makes them hard pests to get rid of.
How do wood ticks differ from American dog ticks?
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Wood ticks and American dog ticks look very alike. Wood ticks tend to be more red in color. Dog ticks are darker brown. The best way to tell them apart is by location. Wood ticks live in western states. Dog ticks live in eastern states.
With five years of hands-on experience in the pest control industry, George Schulz is a registered technician with the Virginia Pest Management Association and a proud third-generation professional in a family business that's been protecting homes for over 57 years. He manages and trains a team of service pros while also leading internal research efforts—recently spearheading a deep-dive review of thousands of documents on pest control materials to hand-pick the most kid and pet friendly, most effective solutions tailored specifically for homes in the DC metro area.