What happens to ticks in winter? - briefly
During cold months, most ticks enter diapause, remaining inactive in leaf litter or other protected microhabitats until temperatures rise above about 5‑7 °C. Fed females may overwinter on hosts, while unfed nymphs and larvae survive in sheltered ground layers.
What happens to ticks in winter? - in detail
During the cold months, ticks enter a state of reduced activity that varies among species and life stages. Adult females of many hard‑tick species seek protected microhabitats—leaf litter, rodent burrows, or cracks in wood—to overwinter. In these refuges, metabolic processes slow, but the insects remain alive, capable of reactivating when temperatures rise.
Larval and nymphal stages often employ a similar strategy. Some remain attached to a host that is itself sheltering from the cold, such as a hibernating mammal. Others detach before the host’s hibernation and find insulated ground litter where humidity stays sufficient to prevent desiccation.
Key physiological adaptations include:
- Diapause induction: Hormonal changes trigger a pause in development, conserving energy.
- Cryoprotectant synthesis: Accumulation of glycerol and other polyols lowers the freezing point of bodily fluids.
- Reduced water loss: Cuticular lipids become less permeable, helping maintain hydration in dry winter air.
Temperature thresholds differ among species. For example, Ixodes ricinus typically ceases activity below 5 °C, while Dermacentor variabilis may remain active down to 10 °C if microclimate conditions are favorable. Snow cover can insulate the ground, keeping temperatures just above freezing and allowing limited movement.
When spring temperatures exceed the species‑specific activation point, ticks resume questing behavior. Females that survived in sheltered sites begin laying eggs, initiating the next generation. The survival rate through winter influences population density in the subsequent season, making overwintering success a critical factor in disease transmission dynamics.