Help! There’s a Mouse in My Apartment

Picture this: You’re alone in your apartment, relaxing on your couch while watching TV. In the distance, you see something that makes you realize you’re not actually alone – a mouse sprints across your kitchen floor or countertops and disappears before you even realize what happened. Unfortunately, seeing a mouse in your apartment isn’t uncommon, especially in urban environments. Here’s how to keep your apartment free of the germs mice can bring, catch the mouse currently invading your apartment, and prevent additional mice from entering.

Why mice in your apartment are a problem

Nobody likes having unwanted intruders in their apartment, but an unwelcome guest can be different from a harmful invader. Mice, unfortunately, are both. Mice urine, droppings, and saliva can contain bacteria including salmonella, which can give you an extended stomach virus, and the extremely rare hantavirus, which can lead to a fatal, flu-like illness. Although there were only 20 reported U.S. cases of hantavirus in 2018 (and only two mice species, both of which tend to live outside urban areas, carry the virus), five of the infected patients died.

Additionally, mice can cause extensive damage to your apartment. Mice constantly chew on anything they can find, including insulation and wires running through your walls. When they do so, they can start fires. Worse yet, mice will eat almost anything, so if your problem becomes severe, you might find mouse droppings near your food or tiny bite marks on your food containers – and your food could be contaminated with mouse droppings, urine, or saliva.

What you should do immediately upon seeing mice

If possible, when you see a mouse in your apartment, figure out where it’s coming from. If you find a hole, seal it with steel wool and, if possible, small nails – mice will chew through most other materials. You should also contact your landlord and seek their assistance in sealing the holes or bringing in an exterminator to do so. 

You should also spray down any areas the mice contacted with bleach or an equally strong disinfectant. This step is especially important, as mice urinate frequently, and their urine tends to contain the germs that make them dangerous. After five minutes, put on disposable gloves and wipe down the bleached area. Once you’re done cleaning, wash your hands thoroughly afterward.

If you encounter mouse droppings, you’ll also want to spray them with bleach and wait five minutes to clean them, but absolutely never sweep or vacuum them, because this aerosolizes the pathogens in the droppings. Instead, after five minutes, put on disposable gloves and pick up the droppings with a paper towel, then dispose of the paper towels and gloves. Take out the trash, and wash your hands thoroughly afterward.

What you should do next

After your immediate post-sighting actions, you’ll need to do even more to keep mice out. If you spot holes anywhere in your apartment – keep in mind that mice can fit through holes as small as dimes – seal those too. Then, do the following.

Put down mousetraps

Set up mousetraps near spots where you’ve seen mice. Whenever you touch or handle the trap after setting it, wear disposable gloves and thoroughly wash your hands with warm water and soap afterward.

You can use poison bait traps or other traps that instantly kill mice, but then you’ll have an animal to clean up. Plus, kids and pets can accidentally come in contact with the poison without knowing any better. That’s why the National Capital Poison Center recommends using non-poisonous traps.

Many non-poisonous traps, however, still kill mice – and some don’t do so humanely. Other traps that catch mice without hurting them are available, and they’re often easy to set up and, upon catching the mouse, release. A transparent mousetrap, for instance, just requires a bit of peanut butter to lure a mouse, and since it’s transparent, you can see when the mouse is caught. Once you’ve caught the mouse, you should release it three to five miles from your home – otherwise, it can easily find its way back. If you’re traveling with the mousetrap, place it in a cardboard box atop several layers of paper towels to prevent the spread of urine and droppings. 

Use peppermint oil

If you find traps ineffective, you can at least temporarily dissuade mice from entering your home using peppermint oil. A water-oil mix that uses one cup of water for every two teaspoons of peppermint oil can be added to a spray bottle and liberally spread throughout your apartment, especially near where you see mice. While this is a common household trick, the merits of using peppermint oil remain uncertain.

Try ultrasonic sound devices

Some ultrasonic sound devices may be able to deter mice from entering your home. However, even more so than with peppermint oil, the merits of these devices remain debated.

How to prevent mice from entering in the future

The best thing you can do to prevent mice from entering your apartment in the future is to seal all possible entryways with steel wool. Look for holes and cracks near or on walls, floors, and foundations.

Additionally, a clean home lacking exposed food sources and crumbs on the floor – mice have no trouble living on crumbs alone if needed – may give mice fewer reasons to enter your apartment. You should also thoroughly seal all your food – including pet food – and use your refrigerator and freezer liberally since mice likely won’t enter them. But cleanliness alone won’t keep mice from showing up – and if they keep coming, it might be time to have your landlord set up an exterminator appointment.

What tips do you have for handling mice in an apartment? Share them in the comments!