How can mice get into an apartment? - briefly
Mice exploit openings as small as ¼ inch, including gaps around plumbing, cracks in foundations, vent covers, and unscreened doors or windows. They also travel along utility lines, sewer pipes, and drainage systems to reach interior spaces.
How can mice get into an apartment? - in detail
Mice infiltrate residential units through a variety of small openings that provide access to food, shelter, and water. Their bodies can compress to pass through gaps as narrow as ¼ inch (6 mm), allowing entry through seemingly insignificant flaws.
Common routes include:
- Cracks in foundation walls or slab edges, especially where concrete meets soil.
- Gaps around utility penetrations such as water pipes, electrical conduit, and HVAC ducts.
- Openings around doors and windows, including worn weatherstripping, damaged frames, and unsealed glass panes.
- Unsealed holes for cable TV, internet, or telephone lines that run from the exterior to interior walls.
- Gaps around vent stacks, chimney flues, and dryer exhaust ducts, particularly where flashing is deteriorated.
- Spaces beneath floorboards, especially in older buildings with uneven joists or missing subfloor panels.
- Openings around plumbing fixtures, such as gaps under sinks, around bathtub overflow plates, and where the toilet base meets the floor.
- Small holes created by rodents themselves, enlarging existing cracks or creating new passages through gnawing.
Additional factors that facilitate entry:
- Improperly sealed crawl spaces or basements, where mice can travel along joists or insulation.
- Loose or missing siding, soffit, or fascia boards that expose interior walls.
- Damaged or missing brick or stone veneer, creating cavities that connect directly to indoor spaces.
- Uncapped or poorly sealed vent pipes on the roof, allowing aerial access.
Preventive measures require systematic inspection and sealing of all identified pathways. Use steel wool or copper mesh combined with a hardening sealant for gaps larger than ¼ inch; for structural cracks, apply expanding foam or mortar. Install door sweeps, replace worn weatherstripping, and ensure that all utility penetrations are wrapped with metal flashing. Regularly check for signs of gnawing or droppings, as early detection limits infestation growth.