Why Do Mice Keep Coming Back? 7 Reasons Your Traps Aren’t Working

You set traps. You caught a few. Things went quiet for a week or two. Then you heard it again: that light scratching in the wall, the fresh droppings by the stove.

If mice keep coming back, it doesn’t mean you’re doing something wrong. It usually means one of a few common problems is still there. Here are the seven we see most often in Minneapolis-area homes, and what to do about each.

1. The way in is still open

This is the big one. Traps catch the mice that are already inside. They do nothing to stop the next ones from walking in through the same gap.

Mice can squeeze through a hole about the size of a dime. In older Twin Cities homes, there are often dozens of small gaps at the sill plate, around pipes, and at the garage door.

Fix: Find and seal the entry points with steel mesh, hardware cloth, and rodent-proof sealant. See our rodent exclusion page.

2. The traps are in the wrong places

Mice don’t wander across the middle of the room. They run along walls, behind appliances, and through hidden paths. A trap in the open usually gets ignored.

Fix: Place traps along walls, with the trigger end facing the wall, where you see droppings or rub marks. Put them behind the stove and fridge, under the sink, and along the basement walls.

3. Not enough traps

One or two traps for a house with a mouse problem isn’t enough. Mice breed fast, and a small group can become dozens in a season.

Fix: Use more traps than you think you need, spaced a few feet apart in active areas. Check them daily.

4. There’s an easy food source

If mice have a steady supply of bird seed in the garage, dog food in an open bag, or crumbs under the toaster, they’ll keep coming back for it.

Fix: Store food in sealed containers, especially in the garage and pantry, and keep counters and floors clean.

5. The neighbors have mice too

In neighborhoods with homes close together, like many parts of Minneapolis, Richfield, and St. Paul, mice can move between houses and garages. Duplexes and apartments share walls, so mice travel between units.

Fix: Sealing your own home is the best defense. In multi-unit buildings, ask the landlord or HOA about treating the whole building.

6. You’re relying on gadgets

Plug-in ultrasonic devices, peppermint oil, and dryer sheets are popular, but there isn’t good evidence they keep mice away for long. Mice may avoid them briefly, then get used to them.

Fix: Stick with what works: trapping plus sealing.

7. They’re nesting where you can’t see

If mice are nesting inside walls, ceilings, or the attic, you may only be catching the ones that wander out. The nest keeps producing more.

Fix: A professional can trace the activity, find the nest areas, and trap at the access points. See mice and rats in walls and attic rodent removal.

When to call for help

It’s time to bring in a pro if:

• You’ve been catching mice for more than a couple of weeks
• You hear noises in the walls or ceiling
• You find droppings in several rooms
• Mice come back every fall
• You think it might be rats

A technician will inspect the whole house, remove the mice that are inside, and seal the gaps so they can’t come back. Learn more on our mouse exterminator page.

Norvane Rodent Control is a free referral service. Calls are connected to independent, licensed pest control providers serving the Twin Cities. We do not perform pest control services ourselves. Learn more.