[Ice Chips] Answers to Your Toughest QA Questons

Q. We are having a hard time getting rid of a mouse that has been sighted in our warehouse. Employees have reported seeing it on pallets and we have found mouse droppings on pallets taken from the upper areas of our rack section. We have mechanical traps around the perimeter but these are not working. We have placed sticky traps where it has been seen. Can we put some traps in the upper rack area? How is this done?

A. You have an issue that requires quite a bit of work to resolve. It appears that you have at least one, if not more, mice that have relocated their living space to the upper tiers of your warehouse. These are typically called pallet mice. They can spend their entire life in a single pallet, get all their resources from upper levels and never touch the floor or see any of the traps in a typical trap placement program. This phenomenon is becoming more common as the mice adapt to the pressures in their environment.

I would encourage you to place traps throughout the upper areas of the racks. A simple way to do this is to roll up paper-backed glue boards and place them in 1.5 inch diameter PVC pipe. The pipe should be long enough to leave 1-1.5 inches of clearance to the glue at each entrance. These can then be secured to the cross supports to eliminate mice traveling between levels. Make sure you number them and map their location so they can all be accounted for.

Now the work comes in. Every pallet on which you find mouse droppings will need to be moved outside, broken down and inspected. Pallets on either side, above and below will also have to be inspected, and if droppings are seen, removed for inspection. If your rack braces have hollow spaces with openings, inspect them thoroughly as potential nesting sites. This can go on for quite some time.

I would also suggest that you maintain the rack monitoring system since a rodent population has already established itself there. Washing and sanitizing the racks will reduce the potential for other mice to pick up and "follow the trail." AIB