Insights · Guide
Calgary and area · Fully licensed and insured
Exclusion vs bait stations: which actually stops mice?
Exclusion closes the gaps mice use to get in; bait stations only kill mice that are already coming. In Calgary homes we close gaps first, then explain any other options at inspection. Bait still has a place, and this guide covers when.
| Exclusion | Bait stations | |
|---|---|---|
| Stops new mice | Yes, at closed joints | No |
| Poison on site | No | Yes |
| Secondary poisoning risk | No | Yes |
| Ongoing | Follow-up as needed | Typically recurring |
How mice get in
A house mouse fits through about 6 mm (Penn State Extension; Pest Control Technology). Calgary’s Chinook swings can take a wall through several freeze-thaw cycles in one winter, and each cycle works sealant and trim joints loose. A joint that was tight in July can be open by February.
When bait stations are the right call
- A heavy infestation where numbers need to drop fast.
- Sealing cannot be done yet (winter roofline, access, renovation).
- Large commercial, agricultural or outbuilding sites that cannot be fully sealed.
Even then, bait works best alongside exclusion, not instead of it.
What a good exclusion job looks like
- A full walk-around, garage to roofline.
- Each joint named and closed with mesh, sealant or metal, not foam alone.
- A written list of what was closed and what is still open.
- A follow-up check.
What you can do today
- ☐ Daylight test on doors and the garage door.
- ☐ Check vent screens.
- ☐ Store food and seed sealed.
- ☐ If bait is out, keep it in locked stations away from pets.
Where to go next
Related reading
Questions
Is exclusion better than bait stations?
They do different jobs. Bait reduces mice already present; exclusion closes the gaps so new ones cannot get in. In a house, exclusion is usually the first step.
When are bait stations the right call?
When there are many mice and sealing cannot be done right away, on large commercial or agricultural sites, or around outbuildings that cannot be sealed. Even then they work best alongside exclusion.
Are bait stations safe around pets?
Tamper-resistant stations reduce the risk of a pet reaching the bait, but rodenticide is still poison, and secondary poisoning can happen when a pet eats a poisoned mouse. We plan methods around pets and kids and explain the options at inspection.
How small a gap can a mouse use?
About 6 mm (Penn State Extension). That is why gaps that look too small still matter.
Does exclusion last forever?
No. Freeze-thaw opens new joints, especially in Calgary. The Gap Guarantee covers re-entry through a specific joint we closed and documented, during the first freeze-thaw season after the visit. It is not a whole-house seal.
Show us the gap.
Text a photo, call, or request a written quote.