Prime tick habitat! Daffodils emerging in leaf litter, Feb 2017 (photo by Kate St. John)

16 March 2026

Warm weather in Pittsburgh this month has drawn us outdoors to work in the yard, walk in the woods and explore with the dog. Many of us, especially the dogs, are encountering an unusual number of black-legged ticks (Ixodes scapularis). It’s already time to take precautions and spray your clothes.

Why so many ticks right now?

• In fall, black-legged ticks burrow under leaf litter to survive the winter. Bitter cold doesn’t kill them if they can hide from it.
• Snow cover acts as a giant blanket that keeps ticks warm. This winter we had -5°F but the ground was snow covered. Perfect for tick survival.

Black-legged ticks don’t need a “wild” landscape (below). Leaf litter in the garden is a perfect place for ticks to hide all winter (above).

Tick habitat (photo by Kate St. John)

Move the leaves or walk in them and you’ll find ticks. This month they’ll all be adults (large tick below). In May the tiny nymphs will appear.

Black-legged ticks: adult and nymph (photo from Wikimedia)

When black-legged ticks suck our blood they can transmit a parasite into our blood stream that causes debilitating Lyme disease. Pennsylvania has the highest number of Lyme disease cases in the U.S.

Reported cases of Lyme disease in US, 2023 (map from cdc.gov)

This year we were caught off guard. Already there are tons of ticks!

Spray Your Clothes and Field Check for Ticks. Click here to learn more.

It’s Spray Your Clothes Day (photo by Kate St. John)