Ticks do not vanish with the onset of cold weather. These arachnids employ various strategies to survive and can remain a concern even when temperatures drop. Understanding how ticks endure colder months and when they might still be active is important for continuous awareness.
How Ticks Endure Winter
Ticks survive freezing temperatures through several mechanisms. A primary strategy is dormancy, or diapause, which slows metabolism and conserves energy. This genetically programmed arrest in development or activity is triggered by environmental cues like changes in day length, preparing them for unfavorable conditions.
Many tick species produce natural “antifreeze” compounds, like glycerol and specialized antifreeze glycoproteins (AFGPs). These compounds lower the freezing point of their internal fluids, preventing ice crystals from forming within their cells and tissues. Ticks also seek sheltered microclimates for overwintering, commonly burrowing into deep leaf litter, under snow cover, or within decaying logs. These protected spots offer insulation from extreme cold and help maintain moisture, preventing desiccation.
Tick Activity in Colder Months
While tick activity significantly reduces in winter, it does not cease entirely. Blacklegged ticks (deer ticks) are hardy and can become active on warmer winter days. They can emerge from dormancy and quest for a blood meal when temperatures rise above freezing, typically around 35-40°F (2-4°C), even if snow is present. Snow cover can act as an insulating blanket, protecting ticks from bitter cold and allowing them to remain viable underneath.
Adult blacklegged ticks are the primary concern during winter, as they are most active in late fall and can remain so whenever conditions allow. Larval and nymphal ticks are less likely to be active until spring, requiring warmer temperatures and longer daylight hours. Therefore, encountering ticks remains a risk, especially in wooded areas, leaf litter, or on south-facing slopes that receive more sunlight and experience thaws.
Staying Safe From Ticks in Winter
Protecting oneself from ticks in winter requires continued vigilance, similar to warmer months. After spending time outdoors, especially in wooded or grassy areas, perform thorough tick checks on yourself, your family, and pets. Focus on areas like the scalp, behind the ears, underarms, and around ankles.
Wearing appropriate clothing can also provide a physical barrier. Long sleeves and pants, tucked into socks or boots, can help prevent ticks from reaching the skin. Using EPA-registered insect repellents on skin and clothing can offer an additional layer of protection. For pets, year-round use of veterinarian-approved tick prevention products is highly recommended. Staying on marked trails and avoiding dense leaf litter or overgrown vegetation can further reduce exposure risks.