Mice or rats living in a house or business
Since mice and rats reproduce rapidly, they can quickly become problematic tenants in buildings that provide a suitable habitat and food source. Unfortunately, many people choose ineffective and inhumane solutions to this problem. The best long-term solution is to exclude the animals from the building by closing off all potential entry points into the interior of the building. It is advised to do this during the spring or summer, when rodents are less likely to be taking shelter in the walls of the building. This involves several steps:
- Identify the Entry Points. Move furniture away from the walls to inspect the entire perimeter of rooms where the animals have been heard or seen, checking for gaps under baseboards, and in areas where piping or electrical cords enter the room. Bear in mind that mice can squeeze through holes the size of a dime! If gaps cannot be located, it may be helpful to sprinkle a thin layer of flour or talcum powder around the perimeter of the room to identify animal tracks and areas of traffic to trace them to entry points.
- Close all entry points by securing wire mesh over the hole (1/4-inch hardware cloth or heavy-gauge screening is recommended) or balling up metal screening or steel wool and stuffing it into the hole. Seal off any cracks or crevices. Holes may be further reinforced by additionally filling them with expanding plaster or caulking. Because rodents can gnaw through these, though, it is recommended to combine them with wire mesh.
- Remove Food Attractants. Small rodents do not require much food, so pay careful attention to cleaning up crumbs (don’t forget those under the toaster!) and leftover pet food.
- Use Humane Live Traps after entry points have been sealed, to trap any remaining rodents inside the building. Traps should be monitored frequently, and trapped animals released immediately outside the building. Relocation of wildlife to a different area is not only detrimental to their survival, but is also unlikely to have any real effect on the rodent population in the area, considering the rates at which these species reproduce. If exclusion is done properly, trapped animals released outside the building will not be able to regain access and will seek shelter elsewhere.
Reminder: Excluding mice or rats from a building is a process that is best undertaken during warmer weather. Releasing animals who have become acclimatized to indoor temperatures and who may not have access to food outdoors during winter is likely to hinder their ability to survive. - Clean the area of any remaining feces.
- Do a close inspection of the outside perimeter of the building if there is no further evidence of animals living in the building. Plug up any holes as described in step 2 (especially looking for gaps where electrical conduits, utility or air conditioning lines, or water pipes enter a building). To ensure no animals are trapped inside, you may use the “paper test” before sealing holes. The paper test can be done by loosely stuffing the entry hole with balled up newspaper. Wait 3 days and nights. If the paper is still in place, the rodents are likely gone, and the hole can be sealed up.
This process takes some effort, but it is the only means to reduce rat and mouse problems in the future. Otherwise, the animals continue to have access to the structure (when indoors), or to a protective habitat (when outdoors) and will be able to reproduce rapidly. Lethal methods cannot provide a permanent resolution to this problem and needlessly kills – in many cases inhumanely – untold numbers of animals in the process. Even live trapping and relocating rodents, sometimes considered as the “humane” solution to wildlife removal, can still be harmful to the animals, and is an endless cycle that does not do anything to prevent the recurrence of the problem.
