Six Tips to Reduce Mouse Callbacks

Editor’s Note: This article was reprinted with permission from Pinto & Associates.

Mice can be frustrating. A widespread mouse infestation, particularly in an old building with plenty of voids and structural deficiencies, can be the very devil to control. Here are some tips to reduce mouse call-backs:

1) Know the territory. Mice have much smaller territories than rats, seldom traveling more than 30 feet from their nest. They prefer to nest within 10 feet of their food supply. If mice are infesting a building, you must learn to see the infestation as numerous small colonies, not one large one. Each area needs to be addressed separately.

2) Think in 3-D when controlling mice. Mice are good climbers. They can and will travel in three dimensions from any single nest site, not just along the floor. Mice can be living above their main food source in suspended ceilings, on top of commercial walk-in coolers, in attic spaces, or inside vertical pipe runs. Or they may be living below in floor voids, crawl spaces, storage rooms, basements, or under coolers and processing equipment. First, visualize a mouse's potential territory as a three-dimensional sphere with a ten foot radius; a sphere that might include the floors above and below, and adjacent rooms. Inspect the entire area -- sideways, above, and below. If you don't find signs of mice, expand the radius of the sphere to 30 feet. Harborage sites must be in this area, which obviously will include the floors directly above and below, and may even include outdoor areas.

3) Make sure you understand the biological and behavioral differences between controlling rats and controlling mice. Mice are very fast breeders. A female house mouse can produce six to ten litters of young in a year, and each of her young becomes sexually active in two months and ready to start families of their own. You can't take your time; the mice aren't going to wait. Technicians need to be persistent, Ideally, you should reservice every infested location every week or two until mouse activity ceases, Otherwise, your traps and baits will only be harvesting some of the population, which are soon replaced through breeding. It also means that you should always use many more placements of baits and traps than you think necessary.

Second, while rats are wary, mice are curious. Mice will investigate any new items or changes in their environment. Don't be afraid to make changes in the account. You can actually improve your control by moving boxes, pallets, furniture, and materials on shelves, and by periodically moving traps or baits to trigger the interest of mice who have been ignoring them,

4) Schedule mouse accounts for regular and frequent follow-up. In heavy infestations, particularly in apartments and commercial accounts, you should inspect every active mouse area every week or two, more often if using traps. First check for continued activity (droppings, gnawings, etc.) and then replace baits and tracking powder and reset traps as needed, This high-intensity follow-up should continue until there is no evidence of continued mouse activity, then service can return to normal. Frequent follow-up is the single most important factor in controlling a severe mouse problem.

5) Don't depend only on customers for mouse-proofing and cleanup. Although this recommendation conflicts with common practice, for problem accounts, some companies have a pricing arrangement with the customer where the technician proactively caulks and seals holes and cracks and sweeps up or vacuums mouse droppings and food debris. With the caulking and sealing materials available today, it is relatively easy for a technician to seal mouse gnaw holes and travel ways.

By vacuuming or sweeping up old droppings, you can gauge mouse activity by noting the number of new droppings appearing since the last service. If there are no new droppings, no further action is necessary. A couple of hundred new droppings means a major feeding, resting, or travel site, and incidentally, an excellent location for trapping or baiting. As an added benefit, removing droppings eliminates a trigger for regulatory action in commercial accounts.

6) Be creative and open to change. Analyze the site and do something different if your service isn't working. Switch to mass trapping instead of baits. Or switch from block bait to pellets, or from pellets to soft bait. Mix and match. Try tracking powder. If a bait or trap is untouched between service visits, move it. If you keep doing the same old thing on each callback, you will keep getting the same unsatisfactory result.

The authors are well-known industry consultants and co-owners of Pinto & Associates.