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Sticker of Western black-legged tick
Bug card No. 4662 of 4,939

Western black-legged tick

Ixodes pacificus
Eats: BloodScorpions, ticks and friendsForests and woods8 legsNot an insect, but a bug cousin

The western black-legged tick is a tiny hard tick from the west coast of North America. It waits on grass and leaves for an animal or person to walk by, then climbs on and drinks blood. It can carry Lyme disease, so it is important to check for ticks after walks.

Fun fact: this one is not an insect. It is an arachnid with eight legs, a cousin of the spiders.
Lives in
The west coast of North America, especially California, in woods and tall grass
Length
2.5 to 3.2 mm (0.1 to 0.13 in)
Top speed
about 0.02 km/h (0.01 mph)
On foot, estimate
Can it hurt you?
Dangerous: look, do not touch
It can spread Lyme disease, which can make people ill. Look, do not touch, and tell a grown-up if you find a tick on your skin. Check yourself for ticks after walks in woods and tall grass.
What does it eat?
Young ticks drink the blood of lizards, birds and small mammals. Grown-ups mostly feed on deer.

Ticks: how to stay safe

  • In Estonia, the castor bean tick and the taiga tick can carry Lyme disease and tick-borne encephalitis.
  • Ticks wait on grass stems, from ankle to knee height. Long trousers tucked into socks and light clothes help you spot them.
  • After playing outside, check your body, your hair and your pets for ticks.
  • Found a tick? A grown-up should take it out quickly with fine tweezers or a tick tool: hold it close to the skin and pull slowly. No oil or alcohol on it. Then wash the spot.
  • There is a vaccine against tick-borne encephalitis, for children too from one year old. Ask your doctor.
  • If in the weeks after a bite you get a fever, feel ill or see a red patch that grows, go to a doctor.

Source: Terviseamet (Estonian Health Board)

For real!Photo of Western black-legged tick
Picture by Kaldari. CC0, via Wikimedia Commons.

How big is it?

How long is it?

Western black-legged tick about 3.2 mm long (0.13 in)A grain of rice about 6 mm (0.24 in)
small enough to sit on your fingernailneeds 3 minutes to cross a dinner table

How big is Western black-legged tick compared to YOU?

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How fast is it?

cool stuff

Fun facts

1

When a female drinks blood, she can swell up to 9.5 millimetres or more.

2

The young nymph is only about 2 millimetres long, so it is easy to miss.

3

A tick usually has to stay attached for about one and a half to two days to pass on Lyme disease, so checking for ticks every day helps a lot.

4

Its whole life, from egg to grown-up, takes about three years.

you asked

Most asked questions about Western black-legged tick

?Where do western black-legged ticks live?

In woods with lots of fallen leaves, in tall grass and along trails on the west coast of North America.

For bug experts

Scientific name
Ixodes pacificus
Group
Scorpions, ticks and friends
Family
Ixodidae
Classification
Arachnida > Ixodida > Ixodidae
Lives on
North America

Where the facts come from

  1. Ixodes pacificus (Wikipedia, CC BY-SA 4.0): what it looks like, where it lives, what it eats, sizes and fun facts, retold in simple words.
  2. Picture by Kaldari. CC0, Wikimedia Commons. The sticker of this bug is drawn from this picture.

If we got something wrong, sorry, we are bug fans, not a science journal. Tell us at [email protected] and we will fix it.

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More from the same group: Scorpions, ticks and friends

Also at home here: Forests and woods

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