Behold, the mighty house mouse


July 13, 2022

Photo: courtesy of, and copyrighted by, Gene White,

The house mouse is ubiquitous in both residential and commercial accounts. Photo: courtesy of, and copyrighted by, Gene White,

The role of mice in the natural environment is well documented, as both food for predators and as predators themselves, feeding on small animals. They also play an important role with seed dispersion. Aside from the value of house mice in our environment, humans have learned to use these animals to their benefit. These include:

  • Training mice to sniff out narcotics and explosives at airports. They have a very strong sense of smell and are fairly easy to train.
  • They are primarily animals used for research in the development of medication, diet and a host of other benefits. Recently, we have been able to create genetically engineered mice that have the same genetic abnormalities found in humans. This allows us to study how to treat humans.

These little creatures have co-existed with humans for thousands of years. During that time, it has become very evident their presence is a threat to our health, food supply and structures.
At press time, U.S. poultry farmers are struggling amid a surge of avian influenza (bird flu) cases. Nearly 23 million chickens and turkeys in 24 states have been killed this year alone because of bird flu. Infections are coming from wild birds — and in part, mice. Many pest management professionals (PMPs) are actively involved in mouse and bird management in the poultry industry. With that in mind, let’s reacquaint ourselves with this small, but mighty pest:

  • Black lights can detect mouse urine, but get to know the odor. Mouse urine has a pungent odor because it contains acetamide. Be able to recognize the smell, to help you find target areas to treat.
  • A dominant male mouse can produce 3,000 microdroplets of urine in 24 hours — and not all in one location. Mouse urine also contains allergens that can trigger asthmatic attacks in children.
  • Mice have a lot to say. They use urine to communicate with one another. They spread their urine with their tails. They also interact as groups.
  • Mice produce 10 to 100 droppings every 24 hours, with an average 50 to 75. A large number of droppings in one location can mean a few mice present for a long time, or a lot of mice present for a short time. Cleaning up the droppings and finding fresh droppings the next day means you still have mouse activity in that area.
  • Mice are capable of making up to 200 visits to a feeding location in one night. You are dealing with a high-energy animal running back and forth to find food.
  • For a mammal, mice mature very rapidly (six to 10 weeks). They have a tremendous reproduction rate. They often mate and conceive while still nurturing a litter; overlapping litters are very common. Thus, neglecting a mouse problem for a few months can result in a lot of extra work to eliminate them.
  • Encountering an adult female mouse that is not pregnant is rare. A dominant male mouse can mate with 20 different females within a six-hour period. Leave a few, and you end up just harvesting mice, not eliminating the population.
  • Mice breed all year round and a one-ounce mouse is well fed and fat. Do not think of mice as a fall-only problem. They do very well all year round.
  • Photo: genxtek/iStock / Getty Images Plus/Getty Images

    Outdoor fall décor can be irresistible to mice and other rodents. Photo: genxtek/iStock / Getty Images Plus/Getty Images

    That said, fall décor such as pumpkins and hay bales provide an excellent harborage and food source for mice. Check and protect the areas that are festooned with such items.

  • Young mice select food in part from the flavor of their mother’s milk. Look at what the mice have fed on to select the best bait for snap traps.
  • Mice are excellent climbers. On a rough wall, they can climb the exterior of buildings several floors up from the ground.
  • Always think in 3D when looking for mice. Some mice never stay at floor level. Placing all your traps
    at floor level will never catch these mice.
  • If you find mice indoors with a thick coat of hair, check the cold areas of the account, such as walk-in freezers.
  • Do not tuck glue boards into corners. While running along a wall, mice often slow down or stop when they come near the corners, and would thus avoid getting stuck in the glue.
  • Mice seek the comfort of shadows. Focus on these six locations during inspection: corners, lines, sebum (grease-like trails), holes, warmth and quiet places.
  • Mice can build up in tight spaces by clustering together. A hollow door might harbor 20 mice.
  • Mice cannot find food from a long distance. You must place your traps and other devices within 10 feet of where they dwell.
  • There are five million viruses on the tip of a single mouse dropping. Mice are potential and active carriers of several disease organisms. Mice have free access into and out of a structure if it is not rodent-proofed. In other words, setting up a rodent-proofing division can be very lucrative.
  • Most mice are nocturnal. This means they are more active at night, when it is quiet and humans are not present. Therefore, when you are trying to inspect and find mouse activity, the best time to do so is just after employees in a commercial account leave. Sit quietly and wait.
  • History repeats itself. Once a mouse population is eliminated and new mice enter, they tend to go back to the same location. Keep written records as to locations where mice were previously found and/or caught.
  • Mice are drawn to hiding in cardboard and cinderblock walls. Check such areas, especially if the cinderblock walls are not capped and the cardboard sits for a while.

Mice will intentionally cover glue boards in their runways with debris. You have to protect glue boards in dusty areas, or use a different approach for control.

The bottom line? Because mice are creatures of habit, you can predict where they most likely will seek harborage.

6 telltale signs of infestation

These are six items to look for when trying to determine the location and severity of the infestation:

  • Fecal droppings
  • Urine odor
  • Sebum marks
  • Footprints in dust
  • Gnaw marks
  • Seeing one or hearing it scurry

Bonus: The answers you receive when you ask people in the suspected area where they think the mice are. — A.F.

Ramp up your retail inspection

In supermarkets and big box stores, mice tend to congregate in certain areas. These are the key locations you should inspect and concentrate your mouse management indoors:

  • Dry dog food department
  • Bird seed department
  • Cigarette shelves
  • Candy aisle, especially where chocolate is sold
  • Employee lockers
  • Suspended ceilings
  • Compressors
  • Stacked charcoal bags
  • Material sitting for a long time
  • Loading docks — A.F.
Photo: Agustin Vai/iStock / Getty Images Plus/Getty Images

Photo: Agustin Vai/iStock / Getty Images Plus/Getty Images

Don’t overlook these apartment harborage areas

To help you locate mice in an apartment, here are 16 locations to inspect:

  1. Non-disturbed areas with warmth and food
  2. Suspended ceilings
  3. Behind plates covering the motors of the refrigerator, dishwasher and other appliances
  4. Hidden voids under sink cabinets
  5. Behind the stove; you must pull it away from the wall, although you need to be careful of tearing up the floor or breaking a gas line
  6. Hollow doors
  7. Closet adjacent to the garbage chute
  8. Broom closets
  9. Wherever pipes penetrate a wall and the opening is not sealed
  10. Behind radiator covers
  11. Underneath dressers and filing cabinets
  12. Couches
  13. Potted plants
  14. Soap in open dishes on the sink
  15. From adjacent apartments (laterally and vertically)
  16. Where pet food and treats are stored
Photo: Saddako/iStock / Getty Images Plus/Getty Images

Photo: Saddako/iStock / Getty Images Plus/Getty Images

Why is my bait gone?

When you place rodenticide bait for a mouse population and it is all gone when you return — but the mice are still there — it can mean different things:

  • You have a large mouse population, and they ate it all because you did not install enough bait stations and bait.
  • Someone “removed” the bait.
  • Ants, cockroaches, squirrels or other non-targets ate all the bait. — A.F.

About the Author

Leave A Comment

Comments are closed.