Mice in Shed

mice seed garage
This began as a small hole in the bag. Before long, mice has spread the seed all over as they ate it.

I grew up in a log cabin in northern Minnesota and our home and the nearby sheds were frequently visited by mice. Most of the time, our cats controlled the mouse population. However, there were times when more were around than normal. Once, while buttering a piece of toast, I noticed tiny lick marks and little foot prints all over the butter in the butter dish. I did not eat toast that morning. On these occasions where the cats were unable to keep up with the mouse population, we would set out snap traps at night. Baited, as you may have guessed, with butter. At night we would lay in bed and listen to the snapping traps, ridding us of our house mouse problem. But you may not want to waste butter, so the following article will offer additional helpful suggestions.

The mice especially liked the shed and garage, where they could go unnoticed for a long time and often find birdseed or other food.

The house mouse (Mus musculus) — the kind you will find in your shed and shop too — is a common nuisance in the homes of people all over the world. The average adult mouse is 3–4 inches long from nose to butt. The tail adds an additional 2–4 inches. House mice have large hairless ears and beady black eyes. House mice are, for the most part, nocturnal and are afraid of bright lights. However, if they’re hungry enough they’ll explore when it’s light out.  Mice are opportunist omnivores. They will literally eat anything.

How Do I Know if Mice are in my Garage or Shed

The most obvious way to confirm mice in your shed or garage is to see them, but short of that, there are a few other telltale signs.

The Scent

Mice will leave an odor in your shed or garage.  It is a hard one to describe, but it smells a little musty and a little “sweet”.  It is actually the odor of the mouse urine, and not one that you want to coexist with.  If you’ve smelled it before, you will recognize it.

Mouse Droppings

Mouse droppings look like little pieces of black rice.  If you see this, there are mouse in your shed or garage.  For us, it is often the easiest way to confirm the presence of mice.

mouse droppings
Mouse droppings, courtesy Wildlife Illinois

Scattered Food

Do you leave birdseed or grass seed in your shed?  If you ever come in and it is suddenly all spread out, that is probably from mice.  It could also be from rats, chipmunks, or birds, but mice is the obvious culprit.

Holes in Insulation

If your shed, garage, or workshop is insulated, you might see little holes about the diameter of a quarter.  This is where mice have eaten their way through the insulation as they burrow and search for more food.

Best Ways to Get Rid of Shed and Garage Mice

get rid of mouse in house

Stop Feeding Mice

The first step in getting rid of mice is to stop feeding them. This also happens to be the best way to get rid of rats, too.

Mice are in your shed or garage because they enjoy the shelter and food it has to offer. So, in order to eliminate the food source, you will have to keep food in sealed containers and clean up your building. Get out the shop vac and suck up all the crumbs on the floor, around a seating area, under the shelving, and anywhere else food may have been left. Pet food is another major source of mouse food. Try only feeding the pets what they will eat in a sitting. If they get a little hungry, maybe they will start going after the mice.

The good news is that cleaning up will also help keep chipmunks out of your shed.

Mouse-Proof Your Shed

In order to keep the mice out of the shed, you will have to mouse-proof your structure. Mouse-proofing inside your shed is a waste of time if they can still get in from the outside. Walk around the exterior of your home looking for holes, cracks, and other possible entry points. Use a combination of steel wool (here on Amazon) and sealant to keep the mice from getting back in through any holes you find. Don’t forget to look under roof eaves as well. Also, make sure any ventilation covers have holes too small for mice to get through—½ inch or less. Make sure all exterior doors have a tight fit with no empty space underneath.

If the shed siding has gaps or holes developing, especially within a couple feet of the ground, patch it. Any visible gap is just asking for mice.

While you’re outside, make sure the garbage bin has a secured lid and that no garbage is laying around for the mice to eat. You may want to try Eco Defense Mouse Repellent (sold at Amazon) to help protect your stuff.

snap trap for mice

Set Snap Traps

Snap Traps are economical and reusable. It also almost always instantly kills the victim. A couple of times I had to finish a mouse off—not fun but not hard.

Trapping mice with a snap trap also gives you the gratification of knowing for sure that you got the mouse, something you can’t get with some other repellent or elimination methods.

Set the traps in places where mice congregate and use some butter or peanut butter as mouse bait. Check the traps on a daily basis, or more frequently if you have a lot of mice. Whenever we heard a trap snap, we would go reset the trap. We would catch 5 or 6 mice before we even went to bed. Use as many traps as you think is necessary. If you are emptying them frequently, set out more. We’d recommend these traps by made2catch sold on Amazon, as they’re easy to empty without having to touch the corpsified mouse.

Use Mouse Poison

Mouse poison may not be safe and is a little controversial, but it is effective. Mouse poison is composed of blood thinner, and it will thin the blood of anything or anyone that eats it. If you have children or pets that might explore our shed or building, I would not recommend using poison. If you do elect to use poison, use covered bait containers to prevent others from eating it.

The other problem with using poison is that it does not kill immediately, giving the mouse time to find a nice hiding spot to die. In time you will become aware of the location, or at least a vague idea, by the stench a rotting mouse corpse provides. Would have been a lot easier to catch it in a trap.

I should note that there is a school of thought, held by many, that poison traps are inhumane and should be avoided. I will let you be the judge based on your personal opinion, but know that if you poison a mouse, the mouse does suffer a slow death. Also know that you create the risk of birds or other animals eating a poisoned mouse and getting poisoned themselves.

Clean Your Shed

yard trash
Waste that doesn’t make it all the way into a sealed trash bin is a feast for mice.

Clear up shelving, floors, workbenches, drawers, cabinets where mice live. After getting rid of the mouse problem, you may still have to find the nests and/or rotting mouse corpses. If you do happen to find a nest, don some gloves and a mask, and throw the nest away. Mice also like to pee and poop around their nests, so you may have more cleaning to do.

Use a weak mixture of bleach water (1 Tbsp bleach to 1 gallon water) to sanitize the area. If you want a more effective and less toxic cleaner, try using an enzymatic cleaner. It has bacteria, which eat up the odor-causing stuff.

It is no surprise that there is a correlation between untidy shed and buildings that attract mice.

Get Rid of Mice Naturally


Some domestic cats are great at catching mice. Not all cats have the instinct to kill mice; the ones that do are known as mousers. If you go the cat route, get a female cat. Females are better at hunting. However, they may leave dead mice in conspicuous spots so that you notice their gifts.

Generally speaking, houses with one or more cats rarely see mice inside.  We don’t know if the mice ever make it in, but if they don’t they don’t last long.  Even the kindest cat has an innate instinct to kill mice.

An added benefit of using cats on mice is that they will find other critters too.  The right cat will even help you get rid of scorpions, believe it or not.


Domestic dogs are not commonly used to catch mice, but a lot of dogs have the ability and will instinctively chase anything that runs from them. Dogs may be a good option as a preventative measure by keeping mice from prancing around your house willy-nilly.

Terriers, often smaller-framed dogs with excellent energy and agility, have long been known to be particularly effective against rodents.

Try a Scent to Get Rid of Mice

Mice are believed to really dislike some natural scents.  These include:oil for mice

  • Peppermint oil
  • Cayenne pepper
  • Cloves

Any of these might keep mice away from a smaller area, but you run the risk of the mouse simply going to a place without the scent, but still in your building.  This can be a good way to keep mice out of smaller cavities in your garage, or small garden sheds.

The best way to use scents is to soak a cotton ball in the oil of the scent.  We like buying bulk-sized peppermint oil (here on Amazon), soaking cotton in it, and then stuffing known gaps where mice like to move around with the cotton.  It also smells pretty good if you happen to get a whiff of it.

How do Mice Get in to My Shed?

Mice get in to your shed by finding the smallest of holes, gaps, or openings to enter through.  It has been said that they can squeeze through a hole the size of a pencil if they have to, but if you have a nickel-sized gap, they will go in and out all day long.

Common places where mice might get in are the gaps between siding and a foundation, gaps around a garage or entry door, and holes in a wood foundation.  Any of those are no match for a mouse.

plug hole bats
Plug any holes or gaps to the shed’s exterior.

Doors, in particular, often do not seal as well on a shed or workshop as they might on a house.  That creates an issue for a steady flow of mice in and out.

One tip is to go inside the shed or workshop, and if you can get to a place with a view of the outside wall, turn all the lights off and look out on a bright, sunny day.  You might see a little tiny ray of sunlight, which can then allow you to ID the hole.

If you find one, stuff it with steel wool (here on Amazon).  Mice can’t gnaw their way through that.

A little mouse problem?

If you choose to neglect your little mouse problem, you may end up with a big mouse problem. Mice are fast breeders. In less than 5 months, those two mice will have 24 children, 64 grandchildren, and 500 great-grandchildren. That is with an average of 8 babies per pregnancy that all survive. OK, so it’s a total exaggeration, but it is possible. The point is that once you realize you have mice, you need to do something about it. Start by finding out what they are eating in your shed. Keep eating areas clean of crumbs, and don’t leave uncovered food out for them to eat. Next, seal up the outside of your house to keep more mice from getting in. Remove waste and other food sources from around the outside of your shed.

Use snap traps inside your house to remove and kill the mice still inside. Even after you suspect you have indeed gotten rid of house mice, keep setting traps and checking them on a daily basis for a couple months. There may still be juvenile mouse hiding in a nest somewhere. If you run across a nest, use gloves and a mask to dispose of it. Geez, maybe you should get a cat. If you do, get a female cat, as they are better mousers.

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