Guide

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Why deer ticks stay active after frost

November to March

Adult blacklegged (deer) ticks stay active through the cold months, questing for a host on days when the temperature is above freezing and the ground is thawed and free of snow. Freezing weather does not kill them, so a mild day in the leaf litter can still mean a tick.

Why this time of year

Adult deer ticks are active from fall into spring in Massachusetts, on days that are above freezing.

How to notice it

  1. Notice the days that are above freezing with no snow on the ground: those are tick days.
  2. Ticks live in brushy and wooded areas and leaf litter, so stay in the center of trails and out of leaf piles.
  3. After being outside, do a quick tick check, especially from the waist up, front and back.
  4. If you find an attached tick, remove it right away with clean fine-tipped tweezers, pulling straight out with steady pressure.

Try this with kids: Can you be the tick-check captain? After coming inside, check a grown-up from the waist up, front and back, then let them check you.

Word to know: “Questing” means a tick climbing up and waiting with its legs out to grab onto a passing host.

Safety

  • Do a tick check after outdoor play or work, especially from the waist up, front and back.
  • If a tick is attached, remove it as soon as possible with clean fine-tipped tweezers, pulling with steady even pressure, no twisting or jerking.
  • If a rash or fever develops within days to weeks after removing a tick, see a doctor.

Sources

  • web.uri.eduUniversity of Rhode Island TickEncounter (university program): 'Blacklegged (deer) tick adults are not killed by freezing temperatures'; can be active on days above freezing; most likely if ground is thawed AND temperature above freezing; not covered by snow; advises 'Always do a quick TickCheck daily, especially from your waistline and up - front and back.'
  • umass.eduUMass CAFE Landscape Message (university extension): 'Adult male and female deer ticks are active any time temperatures are above freezing from October through next May.' Recommends daily tick checks.
  • cdc.govCDC (federal public health, primary): removal with clean fine-tipped tweezers, steady even pressure, no twisting or jerking; remove as soon as possible; see doctor if rash or fever within days to weeks.
  • cdc.govCDC tick prevention: 'Ticks live in grassy, brushy, or wooded areas'; 'Avoid wooded and brushy areas with high grass and leaf litter. Walk in the center of trails.'

Checked against these sources on October 13, 2026.

In the guide for November, December, January, February, March

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