The 5 D’s for successful control of ‘tough mice’ in large facilities

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Large facilities provide mice with unlimited sources of entryways, food and hiding places. Over the years, especially in places with a long history of mouse infestations, mice evolve to be tough and eventually hard to get rid of. “Tough mice” in large buildings are a true challenge for everyone.They are picky, cautious (no longer curious), tricky and knowledgeable of most rodent management tricks.

“Tough mice” are good teachers. They teach their offspring how to ignore rodent control equipment and survive mouse-trapping techniques; hence their persistence. To deal with “tough mice” in a large facility, try the following five tips:

1. Divide the large location into zones or micro areas. This helps in identifying mouse-focused areas. Use current zones designated or used by the facility management to avoid confusion. For example, loading dock area, garbage area, storage area, first level, green area, etc. This helps in monitoring, communication and documentation work.

2. Detect mouse-focused areas and conditions conducive to mouse infestations. This is an important step to identify critical areas in the large facility where mouse management practices need to be centered. Monitor each zone for mouse activity using a well-defined measurement scale for indoor and outdoor activities. Choose a scale that the facility is comfortable with and makes sense. For example, 0 means no activity for three months, 1 means a few activities in a month, etc. To do so, mark each trap/device and record the location of each trap on the location’s schematic. This schematic should be kept current.

3. Design a simple response plan that works, and create a checklist of mouse-active and -vulnerable places. At each service visit, do a thorough inspection as well as any neccessary corrective actions. Routinely inspect mouse-focused zones, paying attention to areas where mice usually enter, thrive or hide, such as garbage and dock areas. While inspecting, look for any fresh rub marks, fresh droppings and new mouse holes. Establish a simple and concrete response plan for each new sighting of mice activity.

The following is just an example of a response plan for a new sighting, you may already have your response plan:

• Locate and bait burrows (put proven loose pellets of baits at least six inches into the burrow).
• Increase the number of bait stations/traps and the frequency of monitoring in the affected area for a set period.
• Mark the supplemental traps and record the location of each trap on the locations’ schematic”. This schematic should be kept current.
• Inspect to locate any entry points or harborage around, above or below the affected area.
• Document and communicate inspection findings, and keep monitoring.

4. Determine whether the treatment is working. Evaluate the mouse reduction progress. Apply risk analysis inspection for each zone at least quarterly. Determine the activity levels for each zone and analyze the monitoring data by answering the following:

• Has the activity level for each zone increased or decreased since your last assessment?
• What has happened since the last assessment to make the difference?
• Is the seasonality one of the factors involved in this change?
• Does the indoor activity level correspond to that of the outdoors surrounding each zone, as applicable? This lets us know whether the mice originated from outside or are breeding inside.

Based on the above information, evaluate your plan and adjust as needed based on your risks assessment finding. No need to keep traps or bait stations that collect dust while catching nothing, remove traps that did not catch anything for more than three months, and place them where fresh and new activities are noticed. Permanent traps/devices should be kept only in critical /sensitive places, such as doors leading to the exterior, garbage area, etc., as applicable.

5. Demonstrate the mouse control development routinely. This is an important step to get everyone involved in the pest management program up to speed on the current situation of the “tough mice” control program. This helps to enlist their support to meet challenges and solve issues as soon as possible. Regular meetings will eventually lead to a team alignment. Make sure that you discuss the current mouse activity level and a list of corrective measures neededCOMMA with responsibilities attached to each measure (who does what). Do not forget to share photos of all conducive conditions to mouse infestations and provide practical recommendations to deal with them.