The Winter Siege: Managing Washington Pests in the Dark & Wet Months

Operational Strategy for December & January

For Washington pest control operators, December isn't the "off-season"—it is the rodent peak.

Right now, we are seeing the "Perfect Storm" for pest pressure:

Soil Saturation: The ground is soaked, flooding burrows.
Freezing Temps: Pests are burning calories to stay warm and need heat.
Human Activity: Clients are cooking holiday meals, creating massive food signals.

Here is your battle plan for the mid-winter grind, based on data from WSU Extension and local health departments.

In summer, rats are content outside. In December, they have two urgent needs: Dryness and Warmth. This changes where you find them.

The Norway Rat (Ground): The ground is currently a wet sponge. King County Public Health notes that rising water tables flush these rats out of sewers and ground burrows. They aren't just exploring; they are evacuating.
- Where to Look NOW: They will jam themselves into the tightest, driest spaces low down—crawl spaces, garages, and under sheds.
- The Winter Tactic: Check the garage door corners. As the rubber seal freezes and stiffens in December, it creates gaps. Rats gnaw through these brittle seals in one night to get to the pet food stored inside.
The Roof Rat (Aerial): These climbers are seeking heat rising from the home.
- Where to Look NOW: They are targeting the roofline and eaves. In December, heat escapes through attic vents. Roof rats follow this heat plume like a map.
- The Winter Tactic: You cannot just bait the ground. You must inspect the roof lines(safely). The entry point is often a construction gap where the facia board meets the roof decking—warm air leaks out here, inviting them in.

Technicians often ask: "It's freezing outside, why does Mrs. Jones have ants on her counter?"

The answer is Internal Foraging.

The Science: In spring, Odorous House Ants (sugar ants) eat honeydew from aphids outside. In December, the aphids are dead or dormant. There is zero food outside.
The Shift: The colony has likely moved inside the wall voids to share the house's heat. They are foraging in the kitchen because it's the only place with food.
The Mistake: DO NOT spray the exterior foundation right now. It is cold, wet, and useless. The ants aren't crossing the foundation; they are already inside.
The Fix:
- Bait Heavy: Use high-moisture baits (gels). Winter heating dries out homes, so ants are thirsty.
- Find the "Heat Spot": Look for trails near dishwashers, hot water heaters, and under-sink pipes. They cluster around these heat sources.

Even if it's not "flooded," the soil under Washington homes is currently saturated.

The Danger: Cold air + Wet soil = Condensation.
Anobiid Beetles: WSU Extension warns that Anobiid beetles (Deathwatch beetles) do their damage slowly in these damp, cool conditions.
The Opportunity: Winter is the best time to sell Vapor Barrier replacements.
- The Pitch: "Your crawl space is absorbing moisture from the wet ground like a sponge. This is rotting your beams all winter long. We need to seal it off."

December and January are some of the darkest times of the year. Your technicians are working in low light, rain, and potential ice.

Roof Safety: Moss + Rain + Freezing temps = Ice Rink.
- Protocol: L&I (Labor & Industries) takes falls very seriously. If the roof is slick, use a pole camera for inspection. Do not risk a fall for a rat check.
Attic Hazards: Roof rats live in insulation. But so do Deer Mice, which carry Hantavirus.
- Protocol: In winter, attics are closed up tight, meaning dust and virus particles stay trapped in the air. Technicians in a lot of cases should wear respirators (N95 or P100) when popping that attic hatch.

IMPORTANT: FOR EDUCATIONAL PURPOSES ONLY

This article is for general information only. It is not legal or professional advice.

Follow the Law: Pest control rules change. Always check with the Washington State Department of Agriculture (WSDA) for current laws.
Read the Label: The label on any pesticide is the law. You must follow it exactly.
Stay Safe: Employers must check Labor & Industries (L&I) and OSHA rules to make sure their workers are safe, especially regarding winter fall protection and respiratory safety.
No Liability: We are not responsible if you use this information and something goes wrong. Use this advice at your own risk.