The Mouse and Rat Invasion
In October, soon after the temperature first dips into the high 30’s, mice and rats start looking for a warm place to spend the winter. It could be in your property.
Since you probably want to avoid having these critters live in anything you own, now is the time to take preventive measures to keep them out. To find out what to do, I talked to Dennis Harvey, landlord and owner of NW Pest Control.
Harvey said the first thing you need to do is an exterior survey of your buildings. What you are looking for is the places where mice and rats can get in. Most common are vent screens that have been kicked in, where cable goes through the wall and pipes where mortar has chipped away leaving a hole through the wall.
Mice need a hole no larger than the size of your little finger, warns Harvey. The largest bone in their bodies is their head bone. They can compress the rest of their bodies to smaller than that. Rats require a larger hole, but have the same abilities as mice to squeeze through small places. Hole’s just a little too small? If it’s wood, both rats and mice will chew it so it becomes large enough.
The holes that mice will slither through are going to be close to the ground, since they are much for climbing. Rats, on the other hand, will climb up drain pipes and go in through holes in the roof, if need be.
When you find a hole, fill it with bronze or lead wool. These products are similar to steel wool, with which we are all familiar, and work the same, but, Harvey warns, steel wool will rust, while the other two won’t. Buy bronze wool at marine supply stores and lead wool at plumbing stores.
Just pack the wool in the hole tightly with your finger or a screwdriver. The mice and rats won’t eat through it, since they don’t eat metal.
While you are doing the exterior survey, look for places where rodents hide, called “harborage” in the pest control trade.
1) Remove all built up leaves from around the foundation to eliminate harborage
2) Caulk any cracks in the foundation to eliminate entrance
3) Repair and replace any broken door sweeps on the house and garage
4) Trim any foliage that may be touching the house to eliminate access to siding
Finally, take, or have your tenants take, these precautions:
• Check bags of grass seed, dry pet food and other material stored in sheds and outbuildings regularly for signs of rodent entry. Move indoors, if necessary, or put in metal or screened bins.
• Separate organic garbage from metal, glass and plastic at the sink.
• Drain the organic material and wrap it in newspaper before placing it in the
• Rodent-proof your garbage cans by setting them on a 12-inch high plat- form and equip them with spring fasteners.
• Maintain a distance of at least 24 inches between the cans and structures from which rodents might jump onto the cans.
• Replace or repair outdoor garbage cans that have holes or lids that do not fit tightly.
• Use enough cans to hold all your garbage. Do not store surplus garbage in cardboard, plastic or paper bags that can be penetrated by rodents.
• Wash out garbage cans periodically so that no organic matter remains after the cans are emptied.
• Never leave garbage cans open during the night, and don’t leave garbage outside in plastic bags.
• Pick up or bury fallen fruit and pet feces daily.
• Put away any foods that pets do not eat between feedings.
What if I have them already?
Harvey explains that there are three effective methods of killing these pests that you can do yourself:
Snap traps. You know these, you can buy them at the grocery store.
Glue boards. These are sticky boards that rodents try to walk across, but stick to. They are the rodent equivalent of fly paper. Home centers and hardware stores will have these.
Anti-coagulant bait. This is slow-acting poison that kills rodents in two to three days. They will go back to their nesting area or somewhere where they feel safe to die. If that is inside your property, you will have dead mice and rats in walls, basements and crawlspaces. If it is outside in a “harborage” area, they will go there.
Anti-coagulant bait is also poisonous to dogs and cats. If they get into it, veterinarians have a Vitamin K1 antidote. Regardless, if you decide to use the poison bait method, check with the store where you buy it to find out exactly how to use it safely. Using poisons around your rental properties opens up a large can of liability worms.
Mice carry 15 different communicable diseases and rats at least that many. That’s not to mention the disease-carrying parasites such as fleas, lice and ticks they can introduce into your properties.
Take a few hours right away to see that rodents don’t invade your rental property.