Wild Mice and Exclusion in Toronto

The initial call to the property was for mice activity in the attic. Often this kind of activity is not from the European House mouse as they cannot climb and jump anymore. They can infest a home and can infest the attic but in their case, it can take time and you will surely see signs of their activities long before they reach the attic. It is more likely that your attic has been infested by native wild mice. Wild mice are native to Ontario and spent most of their evolution without human interaction.

They are not in your home for food, in all likely hood they do not know your house contains food. They live and nest and breed in the attic but hunt for food outside. If you have wild attic mice then you will have trouble telling what it may be. The sound from your attic will be a light rustling and the sound of chewing. If you have attic mice it is important to treat them quickly as they can easily chew through electric wires and cause an attic fire.

Call The Exterminators for a free quote!

Exterior Inspection 

The initial inspection of the exterior revealed a large number of entryways on the exterior of the house. Several wall vents, roof vents and soffit openings were found. Soffit openings, as well as facia vents, roof vents and wall vents, are all common access points for rodents. Mice can fit through an opening as small as a quarter so getting all possible entryways sealed is a smart idea.

Roof vent
This roof vent is open and accessible to rodents and wild animals.
Wall vent and weep vents
A wall vent is easy to access for rodents but did you know an adult mouse can squeeze through weep vents?
Open roof vents
Every open roof vent is an access point.
Roof overhang
Open areas between the soffits and wall can be accessed by rodents
Wall vents and weep vents
More accessible openings.
weep vents
Accessible weep vents.
open roof vent
A very open and accessible roof vent for rodents and wild animals.

Interior inspection 

The interior inspection of the inside of the house found zero mouse activity in the house proper. However, when the attic was inspected the activity was not just high but dangerously so. Mice carry parasites, especially wild mice who can carry fleas and ticks. Ticks can transfer Lyme disease which is an incurable illness and Hantavirus which is a deadly respiratory illness that is common in poverty-stricken countries.

Feces in insulation
A large number of rodent feces was found in the attic insulation.

Initial Measures

The initial measures taken by the technician included laying down tamper-proof bait stations containing commercial-grade rodenticide were placed in areas of high activity in the attic. These bait stations can rapidly kill off a mouse infestation while causing the mice to desiccate entirely when they die. They have no smell and cannot produce bacteria so it is safe for them to die in the walls and insulation.

Proposed exclusion

The proposed exclusion by the technician was involved and encompassing. Six feet of galvanized waterproof steel mesh was used to seal off an accessible area at the front of the house. The soffits were accessible by small rodents like wild mice. Eight Roof vent covers were also installed. Black rubber-coated roof vents with narrow steel openings can allow the roof vent to continue functioning but prevent ingress by rodents and wild animals. Over a dozen weep vents were found around the exterior, while these may seem too small for a mouse to squeeze through they are not and need to be sealed with galvanized steel vented inserts.

Excluded wall vent
This vent has been excluded with a robber-coated galvanized steel cage.
Excluded weep vent
Mice can enter through an opening as small as a quarter.
Excluded weep vent
Weep vents must be sealed off to prevent mouse and rodent entry.
Plumbing vent
Incorrectly installed plumbing vents and electrical can be an easy access point for rodents.
Excluded roof vent
This roof vent could have been one of the access points for the mice. Now they will not be able to get in.
Excluded roof vent
Further exclusion of roof vents ensures the customer will never have attic mice or house mice again.


In conclusion, the exclusion performed on the exterior of the home was highly effective as was the commercial-grade rodenticide treatment on the interior of the attic. The issue has since been dealt with and the customers have not seen any new infestation since.