Will A Cat Keep Mice Out Of Your House?

No. A cat may catch a mouse that crosses the kitchen floor, and plenty of them do, but a pet does not control a house mouse population. The Illinois Department of Public Health states it plainly: cats, dogs and other predators may kill mice, but they do not give effective control in most circumstances. The gap the mouse used is still open in the morning.

That is worth saying in late October, when the question stops being theoretical in Northeast Ohio. Somebody hears scratching above the ceiling, remembers there is a cat in the house, and decides to wait it out. Here is what the research and the state guidance actually say about waiting.

What Happens When A Cat And Rodents Share A Building

They coexist, mostly. The clearest look at it is a 2018 study in Frontiers in Ecology and Evolution, which put cameras on an urban site where free ranging cats lived alongside an established rat colony. Between December 27, 2017 and May 28, 2018 the researchers captured 306 videos of cats and rats using the same space. Out of all of that, there were 20 stalking events and three kills.

Those were rats, averaging around 330 grams, and a house mouse is a fraction of that, so a cat is far readier to take one. The part that carries over is what the rodents did instead of leaving. For every additional cat sighting, a rat was 1.19 times more likely to move toward shelter. Rodents under a predator change when and where they travel. They do not pack up.

The Arithmetic A Cat Is Up Against

A house mouse replaces itself faster than anything in the building can remove it. The Illinois Department of Public Health puts a female at five to 10 litters in a year, usually five or six young each, with a life span of about nine to 12 months. The University of California Statewide IPM Program has them reaching breeding age in six to 10 weeks, and rates house mice as more common and harder to manage than rats.

The second problem is geography. A cat hunts where a cat can walk. Mice spend most of their lives where a cat cannot follow: inside a wall cavity, under attic insulation, behind the kick plate of a dishwasher, in the void around a basement rim joist. UC IPM's number for the way in is a quarter inch, which is a gap you would have to be looking for to notice.

What Gets Left Behind, Caught Or Not

A mouse that lived in the house for three weeks before the cat found it has already been across counters, through a drawer and over whatever is stored in the basement. The CDC's cleanup guidance is to spray droppings and urine with disinfectant or a bleach solution, let it soak five minutes, then wipe it up with a paper towel, specifically so the material never goes airborne. Sweeping or vacuuming dry is the one step to avoid. Our guide to what mice can actually pass on covers the health side, and telling rats from mice walks the cleanup in order.

The Risk That Runs The Other Way

A hunting cat is also the exposure route, which is the half of this question nobody asks about. The CDC tells cat owners that cats usually pick up Toxoplasma by eating infected rodents, birds or other small animals, that a cat can pass the parasite in its feces for as long as three weeks after it is infected, and that what comes out does not become infectious for another one to five days. That is the reason the litter box gets changed daily, with gloves and a handwash after, and the reason someone who is pregnant should hand that chore to somebody else.

Poison deserves the same second look. The National Pesticide Information Center describes secondary or relay poisoning, where an animal is poisoned by eating another animal that has the material in its system, and names pets among the mammals it happens to. The EPA pulled four second generation anticoagulants off the consumer shelf over the risk to wildlife, requires household rodenticides to come packaged in bait stations, and no longer permits loose bait. In a house with a cat that hunts, store bought poison is the wrong opening move. See what pet safe pest control means and, if someone has suggested mothballs, why those do not work either.

What Actually Works In A House With Pets

The order is the same as in any other house, with one adjustment for where the cat goes. University of Missouri Extension is blunt about the limits of tidying up: good sanitation will seldom eliminate mice, though poor sanitation is sure to attract them and let them thrive, and once an infestation exists, some form of population reduction is almost always necessary. Illinois and UC IPM both land on exclusion as the lasting half of the fix, which means the quarter inch gaps outside, not a tighter lid on the cereal.

Our rodent control work is built that way: trapping and monitoring to bring the number down, then sealing the entry points, including gaps as small as a dime. Traps go where the runways are and where a cat or a dog cannot get to them, so tell whoever does the work which rooms the animals have the run of. Our guide to trap placement and the entry point walkaround cover the parts you can do yourself this weekend. If the building in question is a barn, a coop or a feed room rather than a house, the farm version of this problem runs differently.

If The Cat Brings You One Tonight

1. Treat it as evidence rather than a result. One mouse indoors in October is rarely the only one.
2. Note the room and the time. That is the first thing anybody working the problem will ask.
3. Look along the walls of that room for droppings, especially behind and under things.
4. Clean what you find wet, per the CDC, and skip the broom and the vacuum.
5. Walk the outside of the house at ground level while there is still daylight to do it in.
6. Keep the cat out of whatever room the traps go in once a trap line starts.

A good mouser is a nice thing to have. It is just not a rodent program, and a house that keeps producing mice for the cat to catch is telling you something about its exterior. We cover Stark, Summit, Portage, Wayne and Tuscarawas counties, and rodent control in North Canton is where most of this starts. Schedule an inspection through our request a quote page or call 330-494-6199.