Best mouse traps for barns

Why a barn is a different problem from a house

In a house, mice are visitors exploiting a gap. In a barn they are residents, and the building is doing everything it can to keep them.

There is food on the floor. Spilled grain, sweet feed, cracked corn, dropped hay. A barn feed room is the richest calorie source on the property and no amount of trapping changes that.

There is nesting material everywhere. Straw, shavings, loose twine, insulation. You are not going to remove it.

You cannot seal the building. A barn has a dirt floor, a gap under every door, vents you need open and a hundred yards of siding. Exclusion, which is the permanent fix in a house, is mostly unavailable here. Steel wool and copper mesh still has a place around the feed room door and the grain bin, and that is where to spend the effort.

And there are animals. Everything you put down is reachable by something with a nose. That is the constraint that eliminates most of the aisle.

What this adds up to is simple: in a barn, you manage the population rather than eliminate it, and you manage it with cheap devices in large numbers, placed where livestock cannot get them.

Volume beats cleverness

The feed room wall line is the whole game. Mice travel with a flank against a vertical surface, so the inside perimeter of a feed room is a mouse highway, and twenty cheap traps along it will out-catch two expensive traps anywhere else by a wide margin.

A practical layout:

• Feed room: traps every three to four feet along the full inside perimeter, pedal end to the wall, concentrated behind and under the bins where droppings accumulate.
• Tack room: the same, plus the corners of any cupboard with leather or feed supplements in it.
• Open bay and stalls: along the base of the wall behind stacked bales, not out in the aisle where a hoof or a paw finds them.
• Grain bin base: a bucket trap, because that is where traffic is heaviest and where a multi-catch device earns its keep.

Set the whole lot on the same evening. Mice are wary of new objects for a few nights, and putting everything down at once means the wariness expires everywhere simultaneously instead of you chasing the problem round the building for a month. How many mouse traps do I need makes the same argument for a house, and a barn is the amplified version.

The livestock rule

This is the part worth getting right, because a bare snap trap is a genuine injury risk to a curious muzzle or paw, and a barn cat will investigate anything.

Anywhere an animal can reach, the mechanism goes in a housing. A locked bait station with a snap trap bolted inside, or an enclosed snap trap, or a bucket trap with its lid in place. The entrance is mouse-sized; nothing bigger gets in.

Bare traps only behind a barrier. Behind the feed bin, inside a closed cupboard, in the gap behind stacked bales where a horse cannot get a nose in. If you cannot describe the barrier, use a housing instead.

Poison is a bad fit for a barn, and worse than usual. A barn is where the cats, the dogs, the owls and the hawks hunt, and a poisoned rodent is the easiest meal on the property. That is the definition of secondary exposure. If you keep working cats, poison and cats are not compatible on the same site. Mouse trap vs poison has the full case, and is there pet-safe rat poison answers the question people usually ask next.

Bucket traps earn their place here

In a house we are lukewarm about bucket traps, because a house gets checked often and a snap trap is simpler. A barn flips that.

You walk through a barn at feeding time, maybe twice a day, and you are not going to re-arm twelve traps in muck boots with a feed scoop in one hand. A bucket trap resets itself: the lid flips, the mouse drops, the lid returns, and the trap is live again for the next one. One unit can account for several mice between your visits, and that is the single most useful property a device can have in a building you visit on a schedule rather than continuously.

Two practical notes. Run it dry rather than with water in cold weather — a frozen bucket catches nothing and the welfare argument for drowning is not one we are going to make. And give the mice a way up: a plank, a length of two-by-four, a feed sack leaned against the rim. A bucket trap with no ramp is a bucket. Bucket mouse traps covers the mechanics, and do bucket traps work on rats is the honest answer for the larger animal, because a lot of barn rodent problems turn out to be rats.

Make sure it is mice

Worth five minutes before you buy twenty traps. Rat droppings are two to three times the size of mouse droppings and blunt-ended; mouse droppings are rice-grain sized and pointed. A rat run through a dirt floor is a smooth beaten path an inch or two wide. A mouse trap on a rat run will be set off and shrugged off, which costs you a fortnight.

Mice vs rats is the identification page, what size rat trap do I need covers the sizing problem, and if it is rats, best rat traps for chicken coops and best outdoor rat traps are the outbuilding equivalents of this page.

Housekeeping does more than any trap

Trapping is the response. These three things decide how big the population you are responding to is:

Get the feed into metal. Galvanised bins with tight lids. A plastic tub is a suggestion to a rodent; a steel can with a lid is a wall. This single change does more than any product on this page.

Sweep the spill. Daily if you can. Spilled grain in the corners is the reason the population supports itself.

Lift storage off the floor and away from the walls. Pallets, shelves, a clear foot of concrete behind stacked bales. Mice need cover to travel; removing cover removes routes and makes the ones that remain easy to trap.

Then keep two or three traps running permanently in the feed room as a monitor. A barn is never finished — but it can be quiet, and quiet is achievable with cheap traps, a steel feed bin and a broom.