Blacklegged Tick (aka Deer Tick) Ixodes scapularis

The blacklegged tick, or deer tick, Ixodes scapularis, is one of the most important ticks in the Northeast for human and animal health. Blacklegged ticks are common species and the primary vectors for Lyme disease, Anaplasmosis, Babesiosis, and other illnesses. They can be found across the eastern half of the United States and into southern portions of Canada and have a two year life cycle.

Blacklegged Tick Map / Habitat

Blacklegged ticks live across the eastern half of the United States. The northern range of the tick also includes portions of southern Canada.


Visit the CDC website for the most up to date map.

Blacklegged Tick Habitat:

Blacklegged ticks are often found in areas with leaf litter, shrubby plants, and forest grasses. The following images are examples of where you might find Blacklegged Ticks:

Tick Habitat Tick Habitat

Diseases They Can Carry

Blacklegged ticks can carry and spread several pathogens that make people and animals sick. Click on the links below to learn more about the diseases that can be spread through a bite from the blacklegged tick:

Biology and Feeding Habits

1.) Blacklegged ticks are a 3-host tick

  • Blacklegged ticks have 3 life stages when they bite animals: larva, nymph, and adult. Blacklegged ticks are considered a 3-host tick, meaning that one tick will feed from a different host at each of these three life stages.
  • Blacklegged ticks feed for 3 to 7 days, depending on life stage.
  • Visit to see more images of this tick at different life stages.

2. Blacklegged ticks feed on a wide variety of birds and mammal hosts.

  • These ticks feed on mice, chipmunks, deer, and humans.
  • White-footed mice and birds are major hosts for larvae and nymph blacklegged ticks.
  • Adult blacklegged ticks feed on a variety of medium and large sized mammals, like white-tailed deer, dogs, and humans.

Blacklegged Tick Life Cycle

This bookmark briefly summarizes the blacklegged tick life cycle in the Northeast USA across a two-year period:

  • Eggs are laid by female ticks in May.
  • Larvae hatch from eggs in late-June and July, with August being the peak month for larval tick activity.
  • After feeding, larvae drop off of the host and molt into nymphs, which appear in late spring of the next year. May, June and July are the peak months for nymph tick activity in the Northeast.
  • After feeding, nymph ticks drop off their host and molt into adults. Adults appear in the fall of the same year, and can stay active from winter into spring when temperatures are above freezing and snow has melted1,2


  1. ​Stafford, Kirby C. Tick Management Handbook: An integrated guide for homeowners, pest control operators, and public health officials for the prevention of tick-associated disease. Revised Edition, 2007. The Connecticut Agricultural Experiment Station. Available at:
  2. Patnaude, Michael R and Thomas N. Mather. Featured Creatures: Blacklegged or deer tick. Entomology and Nematology Department, University of Florida. Publication Number: EENY-143. Available at:

The TickApp

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The TickApp is a free smartphone app that offers tick identification resources in the Northeast and Midwest USA. It was developed as a Citizen Science Project from our partners at Columbia University!