Mice

Start with what you actually have

House mice are small — an adult body is about three inches, and droppings are the size of a grain of rice, pointed at both ends. If what you are finding is noticeably bigger than that, you have rats, and almost none of the advice on this hub applies. Mice vs rats settles it in about thirty seconds, and it is worth the thirty seconds: a mouse trap will not kill a rat, and a rat trap set for a mouse usually fires without catching anything.

Assuming it is mice: a single mouse is possible, but it is not the way to bet. Mice breed quickly, and the ones you never see outnumber the one that ran across the floor. That single fact drives every recommendation below, because it means the winning strategy is not one clever trap. It is a dozen ordinary ones, set at once, in the right places.

The order of operations that works

1. Find the runways. Mice travel with one flank against a wall. Look for greasy smears along baseboards, droppings in a line, and gnaw marks at the corners of cupboards. Where the droppings concentrate is where the traps go.
2. Set many traps at once, not one. Ten cheap snap traps beat one expensive trap, every time. Trapping is a numbers problem, and most failed campaigns are a numbers failure, not a product failure.
3. Bait small and bait sticky. A pea of peanut butter pressed into the pedal. A large bait lets a mouse eat around the trigger. Best mouse trap bait goes through what beats peanut butter in specific situations.
4. Place them perpendicular to the wall, trigger end toward the baseboard, about every six feet along an active run. Where to place mouse traps has the placements that make the difference.
5. Close the holes. Trapping without exclusion is a subscription. A mouse gets through a quarter-inch gap; steel wool packed into a gap and sealed is the cheap permanent fix.

Which trap, given your situation

There is no single best mouse trap, and any page that says there is has not thought about your house. The choice is driven by three things: whether pets or children can reach the trap, whether you are willing to see and handle the result, and how many you need.

• A plain snap trap is the default. It is instant, it costs almost nothing, and you can afford to set ten.
• An electronic trap solves the handling problem. The mouse dies inside a tunnel and you tip it into the bin without looking at it. It is also inherently safer around a dog, because the shock plates are inside a passage a nose does not fit.
• A live trap is a real option if — and only if — you will check it twice a day and drive the mouse at least two miles away. Otherwise it is a slow death in a plastic box, which is worse than a snap trap.
• Glue boards are the one product on this site we actively recommend against as a kill method. Snap trap vs glue trap explains where they still have a narrow, legitimate use.
• Poison is what most people reach for and the choice we would talk you out of indoors. Mouse trap vs poison lays out why, including the smell in the wall you cannot reach.

What does not work

Ultrasonic repellers are sold in enormous numbers and do not clear an infestation. We say so in detail on do ultrasonic repellers work, including what the published extension testing actually found. Botanical repellent pouches are more defensible, but only for the narrow case they are good at — a stored vehicle, a cabin, a closed drawer — which is what natural mouse repellents covers.

If your problem has a location

Some mouse problems are really location problems, and the fix is different in each. Mice in walls is about trapping something you can hear but cannot see. Mice in the garage is about the room where they usually come in, and where a mouse in the engine bay becomes an expensive problem.