Back to Blog
Rodent ControlOctober 15, 20246 min read

Signs of Mice in London Homes: What to Look For Before It Gets Worse

Learn the early warning signs of a mouse infestation in London, Ontario homes — from droppings to gnaw marks — and when to call a licensed exterminator.

Mice are persistent, adaptable, and quick to breed. A single pair can produce dozens of offspring in a matter of months — which is why spotting the early signs matters so much for London homeowners.

Why London Homes Are Particularly Vulnerable

London, Ontario's older housing stock — especially neighbourhoods like Old East Village, Byron, and Wortley Village — features aging foundations, gaps around utility penetrations, and crawlspaces that mice navigate with ease. As temperatures drop in October and November, mice seek warmth and food, making fall the peak season for new infestations.

The Seven Signs You Should Not Ignore

1. Droppings Along Baseboards and in Cabinets

Mouse droppings are small (3–6 mm), dark, and rod-shaped. You'll often find them along walls, behind appliances, inside cabinets, and in pantries. Fresh droppings are darker and moist; older ones dry and crumble. The volume of droppings indicates the size of the infestation.

2. Gnaw Marks on Food Packaging and Structural Materials

Mice have teeth that never stop growing, so they gnaw constantly. Look for shredded cardboard boxes, chewed plastic containers, and bite marks on wood studs near pipe penetrations.

3. Scratching or Scurrying Sounds at Night

Mice are most active between midnight and dawn. If you hear scratching, scurrying, or soft squeaking in walls, ceilings, or under floors, you likely have an active colony — not a solo visitor.

4. Grease Trails Along Walls

Mice run the same paths repeatedly, leaving greasy smears from oils in their fur along baseboards and at entry points. These dark streaks are a reliable indicator of a well-established runway.

5. Nests in Hidden Spaces

Mice build nests from shredded paper, insulation, fabric, and plant material. Check inside appliance motor housings, in drawer backs, inside wall cavities accessible from damaged areas, and in cluttered storage areas.

6. Unusual Pet Behaviour

Cats and dogs often detect mice before their owners do. If your pet fixates on a wall section, paws under appliances, or acts unusually alert around specific areas, take it seriously.

7. Damaged Wiring

This is the most dangerous sign. Mice chew through electrical wiring insulation, creating fire hazards. If you notice unexplained electrical faults or see chewed cables, treat this as urgent.

What Not To Do

Avoid placing snap traps without addressing entry points — trapping without exclusion is a cycle, not a solution. Avoid poison baits in crawlspaces unless placed by a professional; secondary poisoning of pets and wildlife is a real risk when bait stations are improperly secured.

When to Call a Professional

If you've found more than a few droppings, heard sounds on multiple nights, or discovered gnaw damage, the colony is already established. DIY methods can reduce numbers temporarily, but licensed exclusion work — sealing entry points to 6 mm — is the only durable fix.

Our rodent control process covers the full inspection, trapping, bait station placement, and exclusion work. We follow up to confirm the problem is resolved.

London, Ontario homeowners: Book an inspection or call us directly at 306-990-1278.

Frequently Asked Questions

Related service

Rodent Control

View Service
306-990-1278Book Online