Squirrels in Your Attic in Montreal — What to Do
If you hear scratching or thumping above the bedroom ceiling between 5 and 7 a.m. or 5 and 7 p.m., it is almost certainly a squirrel — not a mouse, not a raccoon. Squirrels are crepuscular (most active at dawn and dusk), they make heavier sounds than mice, and they are the single most common attic-invader species in Montreal residential neighbourhoods.
Two Montreal squirrels you'll encounter
- Eastern grey squirrel — the larger one (450-700g), grey to black coat. Most common in established residential neighbourhoods with mature trees: Outremont, Westmount, NDG, Plateau, Rosemont. They will tear open soffit corners and create entry holes 6-8cm wide.
- American red squirrel — smaller (200-300g), rusty red, white belly. More common in West Island, north shore, and properties bordering forested green corridors. They make smaller entry holes (4-5cm) and are louder and more territorial than greys.
Why they move into attics
Two seasons drive attic invasion:
- Spring (March-May): Pregnant females looking for a safe nest. Litter sizes 3-5. If you have spring activity, assume there are babies within 3 weeks.
- Fall (September-November): Pre-winter shelter-seeking. Solo adults preparing for winter.
How they get in
- Soffit-fascia gap at the roof corners (most common — 60%+ of cases)
- Roof vent — original plastic mushroom-cap vents are easy to chew through
- Eaves trough overflow point where wood has rotted
- Chimney with no animal-proof cap
- Junction where dormer roof meets main roof
Why poison and DIY traps are wrong for squirrels
Three reasons:
- Legal. In Quebec, squirrels are protected wildlife. They cannot be poisoned, and lethal trapping has specific requirements most homeowners don't know.
- Practical. A dead squirrel in an attic wall is a much worse problem than a live one. Smell lasts 6-8 weeks.
- Animal welfare. If there are babies and the mother is killed or trapped without her young, the litter dies of dehydration in the wall — same outcome as #2 plus an avoidable cruelty problem.
What humane eviction actually looks like
- Inspection. Identify the primary entry point and confirm whether babies are present (looking for a nest, listening for high-pitched chatter).
- One-way door installation. A specialty device fitted over the primary entry that allows the squirrel(s) to leave but not return.
- Wait period. Adults leave within 24-48 hours. If babies are present, the mother carries them out one by one over 3-7 days.
- Verification. Confirm no animals remain inside using motion-activated cameras or talc-paper at the entry.
- Seal and reinforce. Remove the one-way door, seal the entry with steel mesh and metal flashing, reinforce all other potential entry points so the next squirrel does not just choose a different opening.
What it costs
- Inspection + one-way door installation + 14-day verification + final sealing: $485-$795
- Properties with multiple entry points or full perimeter exclusion: $695-$1,150
- Insulation removal and replacement (if attic insulation is heavily soiled): additional $1,500-$4,500 depending on attic size — usually only required when squirrels have been present 12+ months
FAQ
Can I just bang on the ceiling and scare them out?
No. They will leave for 30-60 minutes and return through the same entry. The only way to stop them returning is to seal the entry — and the only safe way to seal it is after confirming all squirrels are out.
What about the babies?
Spring callouts are 70% likely to involve babies. If we find a nest, we wait the mother out (one-way doors do not function when babies are present). The wait period is 4-8 weeks before babies are mobile enough to follow the mother out. We monitor weekly during that period.
Squirrels in your Montreal attic?
Humane eviction. Same-day inspection. Permanent sealing. EN & FR.