Winter Is Here—And So Are the Rats: Why Persistent Cold-Season Rodent Intrusions May be the Plumbing
Every year, as temperatures drop across the northern U.S., pest management professionals brace for the same predictable surge: rats seeking warmth in homes, restaurants, and commercial buildings. It’s one of the oldest, hardest facts in our industry—winter drives rodents indoors. And for many clients, this annual invasion happens like clockwork.
Most PMPs respond the same way: seal the exterior, reinforce exclusion, and reset monitoring devices. But if you or your customers experience repeat winter intrusions every single year, even after multiple exclusion attempts, then it’s time to face a truth the industry rarely talks about:
**The problem may not be the exterior at all. It may be the plumbing.**
Cold Weather Drives Rodents Into Sewer Systems—And Right Into Your Accounts
When temperatures drop, rats don’t simply hide in garages and attics. They head underground. Sewer systems offer exactly what rodents need for winter survival:
- Warmth provided by shelter inside sewers and pipes
- Shelter in long stretches of protected pipe
- Unlimited food sources created from organic materials flushed down drains
- Harborage inside private lateral lines
- Cracks
- Breaks
- Misaligned fittings
- Unsealed clean-outs
- Improperly installed pipes
…then rodents can exit the plumbing system directly into wall voids, utility chases, crawlspaces, and mechanical rooms. From there, infestations begin behind the walls, far from exterior entry points.
This explains the most frustrating winter scenario PMPs face:
“The structure is sealed tight, but the rodents keep showing up.”
For decades, that scenario led to one response:
“Call a plumber.”
PMPs knew the plumbing might be involved, but lacked tools to confirm it.
Plumbers often lacked pest-focused diagnostics.
And customers ended up caught in the middle.
That ends now.
The Sewer Assassin™ System: Finally Giving PMPs Control of the Plumbing
The Sewer Assassin system gives pest control professionals something they’ve never had before: the ability to inspect, diagnose, monitor, and control sewer-based rodents directly inside plumbing systems.
Step 1: Prove the Problem With a Clean-Out Station
By installing a Sewer Assassin station at any 3″ or 4″ clean-out, PMPs can instantly evaluate plumbing activity.
Just attach non-toxic monitoring bait to the holder.
- If the bait stays untouched → plumbing is not the source.
- If the bait disappears → you have direct evidence that rodents are active inside the plumbing system.
This alone solves one of the industry’s oldest diagnostic challenges.
But this system goes much further.
Introducing FogTrace™: In-House Plumbing Smoke Testing—Without Candles
Once plumbing activity is confirmed, PMPs can now take diagnostics into their own hands.
The FogTrace Plumbing Smoke Test Machine allows techs to conduct full-scale smoke tests using a clean, non-toxic fog—no more outdated candles, no more special-order supplies, no more relying on outside contractors.
This gives PMPs the ability to:
- Identify hidden plumbing breaches
- Pinpoint where rodents are escaping into interior voids
- Document issues for the customer
- Provide a clear, professional report to guide a licensed plumber
- Keep testing revenue in-house
FogTrace is the modern solution the industry has been missing.
link to fogtrace page
Step 3: Turn Sewer Assassin Into a Permanent Bait Station
Whether plumbing repairs happen immediately or not, the Sewer Assassin can now be converted into an ongoing sewer-based baiting and monitoring station.
This transforms what used to be an “unsolvable seasonal headache” into:
- A controlled access point directly in the plumbing
- A prevention system stopping future rodent migration from the city sewer, into private plumbing
- A new, reliable revenue stream as part of ongoing treatment programs
PMPs now have the power not just to diagnose—but to control sewer-based rodent populations at their source.
Winter Rodent Intrusions Don’t Have to Be an Annual Tradition
If your customers experience winter rodent problems year after year, and exterior exclusion hasn’t solved it, the plumbing may be the missing piece.
The Sewer Assassin + FogTrace system gives you the tools to:
- Confirm sewer rodent activity
- Conduct your own smoke tests
- Find breaches
- Document intrusions
- Guide repairs
- Stop future invasions at the sewer line creating a new regular service.
This is the future of winter rodent control—and PMPs finally get to own it.
Ready to keep rats out in the cold where they belong?
Take control of sewer-based rodent entry points, expand your service offerings, and stop losing revenue to outside contractors.
**Get the Sewer Assassin + FogTrace System today—
because rats don’t pay rent, and they sure as hell shouldn’t be warming up inside your accounts.**
FAQs About the Sewer Assassin™ Pest Strip Holder: The First System to Treat Sewer-Based Pests at Their Source
1. Why do rodent infestations increase during winter?
Cold temperatures push rats underground into sewer systems where warmth, shelter, and food are abundant. From there, they travel through private plumbing lines and enter structures—even when exterior entry points are sealed—making winter the peak season for hidden rodent intrusions.
2. How can plumbing allow rats to enter a home or business?
Cracked pipes, broken fittings, unsealed cleanouts, or improperly installed plumbing create hidden openings inside walls and utility spaces. Rats follow sewer lines, exploit these breaches, and appear inside buildings—bypassing exterior exclusion entirely.
3. How can PMPs confirm if rodents are entering through the plumbing?
By installing a Sewer Assassin clean-out station with monitoring bait.
- If the bait is untouched → plumbing is not the source.
- If the bait is eaten or disappears → rodents are active inside the plumbing system.
This provides clear evidence and eliminates guesswork.
4. Why do winter rodent problems return every year even after exclusion?
If the plumbing system is the entry point, exterior sealing will never stop the intrusions. Rodents are entering from underground sewer lines, not from the outside. Until plumbing breaches are diagnosed and addressed, rodents will continue emerging inside structures each winter.
