Yes, mice can get through window screens by chewing. Intact fiberglass or aluminum mesh is too fine to squeeze through, but a mouse can gnaw an opening in standard screening in minutes.
Window screens keep out flies. They were never built to stop rodents, and mice figure this out quickly.
People tend to underestimate just how much rodents can chew. Their incisors grow continuously like human fingernails and have to be filed down. They cut through wood, plastic, rubber, and soft metals. Fiberglass screen mesh is barely an obstacle. Aluminum screening fares a little better but is not on its own enough to stop determined mice. Once there is an opening, other mice use it too, because the gnawing and the scent both draw more in.
Screens fail in other ways as well. Frames loosen and pull away from the sill, which opens a gap along the edge. Spline dries out and lets the mesh sag. Basement and garage windows, often older and less maintained than the rest of the house, are frequently the worst offenders in Boston Metro South homes. And a screen with any tear is simply an open window as far as a mouse is concerned.
A full-grown mouse can fit in a hole the size of a dime. If a space isn’t quite big enough, they chew until it is.
To fix this problem, you need better material. Replace damaged screening and tighten loose frames. For windows at ground level or near vegetation, back the screen with hardware cloth, which mice cannot chew through. Check that basement window wells are clear and covered. Then also check for gaps under doors and settle cracks in your foundation. Rodents will often even use the spots where pipes and cables pass through a wall to gain entry to your home.
If mice are chewing their way into your house, Mosquito Squad of Boston Metro South can help. Mosquito Squad finds how mice are getting in, clears the ones already inside with traps and bait stations, and seals the entry points with chew-resistant materials. Annual inspections will help you protect your home as new gaps open.
