Ask the Expert (Pest Control)

How can we solve a rodent problem?

• By Drew McFadden
• 10/01/17

It’s critical that pest problems be identified and addressed quickly, as rodents breed rapidly — a single pair of rats can multiply into 640 within a year, and mice can multiply to over 1,000. Stopping them for good means finding the points of entry and sealing them up to prevent future invasion. Following are some of the most common entry points and exclusion solutions. Remember, when conducting your inspection that mice can fit through a gap of about one-quarter of an inch, and rats through a gap of three-eighths of an inch.

Common Entry Points and Solutions

• Exterior doors. Damaged or worn out sweeps are one of the most common entry points. Most standard brush or vinyl sweeps are good at keeping out the weather but not good at keeping out mice and rats. All doors should be fitted with specialized rodent-proof door sweeps.
• Vents and grilles. These should be protected with screen or mesh. Ensure any voids or gaps around them are filled with a pest-exclusion fill material.
• Drain pipes. Rats are excellent swimmers. Make sure exterior drain and sewer access points are covered with an appropriate metal cover. Openings surrounding the drain should be patched or filled with exclusion material.
• Vertical wires and pipes. Mice and rats are excellent climbers. Circular rat guards should be placed around all vertical wires and pipes.
• Utility and other building penetrations. Check the places where pipes, wires or HVAC enter the building and fill any gaps with a pest-exclusion fill material.

Ensure the exterior of the building, especially around the foundation, is free from harborage areas such as shrubs and ground cover, and eliminate any “bridges” to the roof, such as overhanging trees.

This article originally appeared in the issue of .