Mosquito sitting in the snow
How Fleas and Ticks Detect Hosts, Even in Cold Weather
When temperatures drop, most of us assume that fleas and ticks go dormant, leaving us and our pets in peace. However, even in cooler weather, these pests remain active in search of their next meal. Fleas and ticks have remarkable survival adaptations that allow them to detect and latch onto hosts, even when it’s chilly. Here’s a look at the fascinating ways fleas and ticks sense hosts during the colder months and how they manage to stay active in the winter.
Fleas: Staying Ready for Warm-Blooded Hosts
Fleas are resilient, especially when it comes to detecting hosts. Although they become less active in extreme cold, many fleas survive winter by staying indoors or finding cozy spots in the environment where they can remain dormant in their immature stages (eggs, larvae, and pupae). When they sense a potential host, they’re ready to spring into action—even in cold weather.
- Sensing Body Heat
Fleas are naturally drawn to the warmth given off by warm-blooded animals. This sensitivity to body heat enables them to detect a passing host, even when temperatures are low. Pets, such as dogs and cats, naturally attract fleas because they radiate heat, providing fleas with the signal they need to leap and attach. - Detecting Carbon Dioxide
Fleas also sense the carbon dioxide (CO₂) that animals exhale. Fleas, particularly adults, can detect the CO₂ in exhaled air, allowing them to pinpoint the source and move closer to a potential host. In winter, this adaptation enables them to detect animals even in slightly colder conditions. - Vibration Sensitivity
Fleas are attuned to vibrations and movements in their environment. When a pet or a person moves, the vibrations signal the presence of a host nearby, activating the fleas to move toward it. Even in colder temperatures, these vibrations can trigger a response from fleas, helping them find food in the winter months.
Ticks: Cold-Weather Experts in Detection
Ticks, especially certain species like the black-legged tick, are quite resilient and can remain active in temperatures as low as 40°F (4°C). This ability allows them to detect and attach to hosts during mild winter days or in warmer climates where temperatures don’t drop significantly. Ticks have an impressive array of detection mechanisms that make them effective host hunters, even in the winter.
- Haller’s Organ
Ticks have a unique sensory structure called Haller’s organ, located on their front legs. This specialized organ helps them detect chemical cues like CO₂, body odors, and temperature changes. During winter, this organ is particularly useful, as it allows ticks to sense animals moving through their environment, even in cooler conditions. - Sensing Moisture and Heat
Ticks are drawn to heat and moisture, both of which are present on warm-blooded animals. In the winter, animals radiate heat that creates a contrast against the colder environment, making it easier for ticks to detect them. Additionally, the moisture from animal breath and sweat helps ticks locate hosts with remarkable accuracy. - Questing Behavior
Even in winter, ticks use a behavior known as “questing” to find hosts. Questing involves ticks climbing to the tips of grasses or shrubs, extending their front legs, and waiting for an animal to brush past. With the help of Haller’s organ and their sensitivity to movement, ticks can still detect and latch onto hosts that cross their path in colder weather.
Why Flea and Tick Prevention is Essential Year-Round
Many people stop their pet’s flea and tick prevention treatments during winter, assuming the cold will keep these pests away. However, as we’ve seen, fleas and ticks are more than capable of detecting and attaching to hosts in cool weather. Indoor environments and fluctuating outdoor temperatures mean that pets are at risk year-round.
Preventative Measures
To protect pets during colder months, continue using flea and tick prevention products. Additionally, regular grooming, checking pets after outdoor activities, and keeping your yard free of leaf litter can help reduce the risk of these pests attaching to your pets.
For more information on year-round flea and tick prevention, see the American Veterinary Medical Association’s Guide.
Internal Link: Read more about effective ways to keep your pets safe in winter with our Winter Pest Prevention Tips.
