Blacklegged Ticks (Deer Tick, Bear Tick)

Minnesota Department of Health



Black-legged, or deer ticks, can transmit Lyme disease to humans.

The scientific name of the blacklegged tick is Ixodes scapularis. Many people still know the blacklegged tick by another common name, the deer tick. You may also hear it called the bear tick. They are all the same tick.

The blacklegged tick is much smaller than the wood (or dog) tick.

Adult females and nymphs can transmit infections through their bite.

Blacklegged Tick Life Cycle

Blacklegged ticks live two to three years and have three blood meals. The life cycle begins when the female lays eggs. As the eggs mature, they develop into larvae, then nymphs, and finally adults.

Larval ticks

From May through September, eggs hatch into larvae (plural).

The larva (singular):

is the size of a period at end of sentence

initially does not carry diseases such as Lyme disease, human anaplasmosis, or babesiois

may pick up diseases during its first meal from a diseased host

Larvae usually feed on white-footed mice or other small mammals.

If the mouse is infected with disease-causing organisms, the larva will become infected and be able to transmit these organisms during its second or third feeding

The tick may also feed on a small mammal or bird that is not infected. These ticks cannot transmit disease in later feedings.

After this feeding, the larvae molt into nymphs and become dormant until the following spring.

Nymphal ticks

In the spring and summer of the tick’s second year, primarily from May through early July, the nymph becomes active and takes its second feeding from a mammal.

If the tick is carrying disease agents from its first feeding in the larval stage, it can transmit them during this second feeding.

If the nymph was not already infected, it can become infected if the second meal host is carrying disease agents.

The nymph is about the size of a poppy seed. Nymph stage ticks often look like a speck of dirt or a freckle on a person’s skin.

Adult ticks

In the fall of the second year, nymphs molt into adult ticks. Female adults are red or orange and larger than males.

The adult female ticks feed and mate on large animals in the fall or early spring. The female lays her eggs, then dies.

If the ticks did not get a blood meal in the fall, they go dormant over winter and seek a meal in the spring. A frost does not kill blacklegged ticks. Adults may become active as soon as it is above freezing. They are occassionally spotted during a temporary thaw in the winter.

As female ticks feed over the course of several days, their bodies slowly enlarge with blood (engorge). Adult females infected with disease agents as larvae or nymphs may transmit disease during this feeding.

Male ticks attach, but do not feed or become engorged. Because the adult males do not take a blood meal, they do not transmit Lyme disease, human anaplasmosis, or babesiosis.

Feeding and blood meals

Blacklegged ticks feed on blood by inserting their mouth parts into the skin.

They are slow feeders and will feed for 3-5 days.

If the blacklegged tick is infected, it must be attached for 24-48 hours before it transmits Lyme disease, and at least 12-24 hours to transmit human anaplasmosis.

Blacklegged Tick Habitat

Where do we find blacklegged ticks?

Blacklegged ticks live in wooded, brushy areas that provide food and cover for white-footed mice, deer and other mammals.

This habitat also provides the humidity ticks need to survive.

Exposure to ticks may be greatest in the woods (especially along trails) and the fringe area between the woods and border.

Blacklegged ticks search for a host from the tips of low-lying vegetation and shrubs, not from trees.

Generally, ticks attach to a person or animal near ground level.

Blacklegged ticks crawl; they do not jump or fly. They grab onto people or animals that brush against vegetation, and then they crawl upwards to find a place to bite.

White-tailed deer live throughout Minnesota, but blacklegged ticks are not found everywhere that deer live.


Ticks latch onto skin where they feed on blood.

What can be done to control tick populations?

There are measures you can take to reduce the number of ticks around your home. In general, drier conditions mean fewer blacklegged ticks:

Keep lawns mowed, brush trimmed, and leaf litter away from the home.

Keep trails or paths in wooded areas on your property clear of vegetation.


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