Keeping mice and rats out of storage sheds

I store apples in an out building tool shed.  This last year, I realized that rats had entered into the building. I couldn't figure out how they got in there.  The previous owners, who built the shed, had only put tools and chemicals in there.  I looked around the back of the building and noticed that the gravel had been lowered consistently around the outside.  The vermin must have moved the gravel to low enough to where they could squeeze their way in! I decided to put concrete all the way around the outside of the tool shed so that they couldn't dig their way down and squeeze into the building.

Check it out:
John S
PDX OR

I had to draw the gravel back so I could make the concrete thick enough to stay solid.  Soon, I will move the gravel back to discourage them further.

JOhn S
PDX OR

Hopefully your excellent reinforcement will do the job!

One year I hung apples in a bag from the ceiling of the barn and the critters still got to them!

If they find another way in the shed, you might have to consider rat-proof boxes to store the apples in? You need air flow. They've tried to chew their way into plastic barrels and buckets.

Our ancesters were hip to this and developed a common-sense solution known as 'staddles'.

They are essentially stones carved into 'mushroom' shaped pillers that the sheds or barns are built on top of. Their shape & design prohibits rodents from climbing them and they are tall enough to keep them from jumping up into the shed/barn.

Maybe not practical in the world of today, but I find them to be an ingenious solution to an age-old problem!


https://ruralhistoria.com/2023/10/21/what-are-staddle-stones/

I think the popularity of cats was related to this as well.
John S
PDX OR

Rats are rather intelligent little creatures, and they'll eat most anything so having them in the general vicinity is not good for most homesteading endeavors. As apparently many of us have found out.
We found that once you find where the rats are getting in or frequenting if you start putting out rat traps with some type of bait, they will at first be easily caught.
After catching several rats and plugging up some of the entrances that were found, we saw that the rats being rather intelligent realized that sticking around would not be in their best interest in the long run and generally they just leave!
As much as I hate using traps, we found that on the several occasions that rats had visited our homestead using the traps and plugging holes sent them on their way rather quickly.

It's good that you've used concrete to try to fill as many access points as possible; that's a permanent solution.

For any other opening (say, for ventilation), put 1/4" galvanized mesh over it.
1/4" mesh is the largest you can use and keep the mice out. If the gaps are larger, mice will get through.
This option also provides ventilation.
(This mesh is also good for putting around trees, to prevent mice from gnawing on the bark and ringing the trees. It needs to be buried a little in the dirt to prevent them from digging underneath.)

I have found that building a shallow planter for containment of mint around the shed keeps most critters out. My last one was about a foot wide and 6 inches deep on top of pavers {to keep the mints in) and planted my mint collection. Don't forget to mulch it.  For the door sill a line of salt with mint oil will keep it rodent free.

I had a suspicion that I hadn't found all of the entrances. Then I heard noises.  Then today, I saw a mouse.  Where was the other entrance? I went to the front of the shed, below the ramp the previous owners had installed, there was a very long slot, that was about 1/4" to 1/2" wide.  Even more CSI: it had old remnants of apples left in it.  It even dropped down really low to where a mouse, but not a rat, could climb down and slide his little body into the tool shed.  I filled it almost to the top with 1/4" gravel. I wanted to leave enough room for the concrete to have a little internal toughness so the critters won't keep clawing their way in.    I didn't put cement/concrete in yet, because it is going to rain heavily tonight and tomorrow.  I left it as is, so I can see if there is any movement in the next couple of days.  


Then I will fill it up with cement or concrete.  It won't be as thick as the other concrete around it, so it might crack in some places, but it will be tough enough to stop a mouse from digging his way in.  

One thing I remember: I had left a tall (12'?), wooden measuring stick for the oil tank leaning against the door a few years ago.  They managed to climb up the stick and into the tool shed.  

Also, today, I filled in the cement on that last slot after the rain had stopped.  Hopefully, that will be the end of it.

John S
PDX OR

I found that the mouse had eaten some more apples, so I got worried. After all of the concrete work was finished and solidified,  I did a test run to see if the nibblers were still in there. I left out an apple in the open, not in any box or anything. I've done that before to see if there is something alive in there. Last time, one was alive and ate the apples.    And this time?........

The apples were left untouched.  The latest cement sealing seems to have worked.  Now I can actually store what's left of my apple harvest in there.  I know that it is likely that at some point, I will find a dead mouse in there somewhere.  Oh well.  

Nice to know that the harvest can continue now. I had a run of 15 years before they figured out that sneak entrance route.

John S
PDX OR

If it’s feasible I’d add a cat or two to the arsenal along with something like this..  I don’t think it would be hard to cobble one together.  Depending on your sensibilities you can use it either dry or about half full of water.

For either a talented or a curious person, that could be a really fun and exciting project! Our cat is an indoor cat and he would run away and get eaten by coyotes.  

Good ideas.
John S
PDX OR

Thanks, John. :)  Just for info, at least around here most veterinarians have barn kittens to get rid of or know where some are at.  Mine are all rescues, spayed and neutered.  They do their jobs well and we take good care of them.  Last night we found Bob playing with a rattlesnake in the front yard.

I recently relocated to an older home, still in the country, and befriended a stray cat last winter. Poor thing was half starved and looking for food and warmth, but I couldn't bring it in b/c I have 2 housecats. Over the winter I made a bed for it in a dog crate I had on the back porch and left food and water out. Fast forward to the spring and suddenly I see 5 kits plus mama. She had brought them from the woods to the crate. As the kits grew, I watched them have a feast on the mice they caught under the house and in an old shed, and still providing food for them, they're all now huge but feral and wander the neighborhood. Interestingly (not) a couple of my neighbors have commented about how they're not seeing as many mice as they usually do this time of year. A bag of kibble is a lot cheaper than having to replace a lot of food in the pantry if they get in the house or having to repair damage to walls etc.

https://www.youtube.com/@ShawnWoodsMousetrapMonday

I have his "dizzy dunker" mouse/rat trap coming.

I'll post a review when it gets here.

It sounds like you've taken an excellent step in preventing rats from entering your tool shed by pouring concrete around the perimeter. Rodents can be quite crafty, often exploiting gaps or changes in the terrain to gain access. In addition to your concrete barrier, ensure you seal any potential entry points, such as cracks or gaps around doors and windows. Keeping the area around your shed clear of debris and regularly checking for signs of rat activity will also help you maintain a rodent-free environment. Combining these efforts should significantly enhance your protection against pests!

Last night after one last check outside to make sure food and water was on the porch, I saw one of the kits playing with a skunk! Oh h___ no, I screamed, told them they were on their own, and ran back inside. They've already befriended an opossum and a racoon and don't mind them coming up on the porch to finish the kibble bowl. I do draw the line with skunk tho. No more food left out!

Last winter for the first time I discovered traces of mice being in my house! Yes, not in the shed, but here where I live!
I live here since 2004 (in fact it is a ground-floor apartment, part of an apartment building built in 1960) and never before we had a mice problem. I think that was thanks to having a dog. Not a dog hunting and eating mice (although Jack Russel terriers are known to be mouse/rat hunters), but the fact that the smell of a dog discouraged the mice to come in. Now doggie Toetie had died 2 years ago and there is no new dog, nor cat, the mice dare to enter.
First they were in the pantry (small droppings, a hole in a cardboard box). Then I even saw a mouse in my living room! So I went to search for the openings where they could enter the house. I already found two small openings that might have had connection to the empty space under the building (in the foundations). I put 'steel wool' (from pan scrubbies) in the holes, I read that's a solution because mice can not destroy the steel threads with their little sharp teeth.
Maybe it helped. For several months I did not see any mice here. But now winter will start again, I'll be attentive ... Keep eyes and ears open.
If I notice mice again, I will borrow a cat (only for a few months)!

My next door neighbor lives in a house even older than mine, and has had an invasion of mice over the last couple of years (she has no cats). She read putting cloves down and around places where she was seeing mice prior helped. She went the peppermint, the steel wool, the tin foil  and other things route, and the mice just ignored it. So far, she said this winter she hasn't seen evidence of any. I've even been putting cloves under the seat in my car b/c they eat the wires. So far so good.

John S, if in the future if your rodent problem should return and you are at wits end as what to try next. I would suggest mixing some of the Portland cement with corn meal, add a pinch of salt, place a small bowl in the shed with a bowl of water close by.  We all know what happens when the water mixes with cement!  This does work and is non-toxic. The only problem is if the rodents die under the shed or within the wall, well lets just say it is somewhat unpleasant for a period of time.

Peace

I feel like Al Pacino in the Godfather, part 3: Just when I thought I was out, they dragged me back in!

Not mouse free. I heard and saw them.  So I noticed on the corrugated steel door, there is enough wiggle room for them to sneak in around it.  I remembered when I was a kid, we made clay out of dough. It hardened after awhile. I thought, cheap, it might work.  No.

They avoided it for a couple of days, but the "clay" stayed wet and oozed.  I also noticed there were some gaps at the top part as well.  I hammered and screwed in boards to make sure they couldn't sneak in at the top with the gaps there.  
JohN S
PDX OR

They *know* it's a dry place with yummy food. They will test your defenses but I have faith that you will win!

AAAAGH! Then I found them in there again! What to do?   I noticed there were slight gaps in the corner, so I shoved some pieces of wood in there so they couldn't get in that way.

Then I saw them in there again.  I decided to make small, stopper pieces of wood for every part of the corrugated steel door, and jammed them in there, so they couldn't wiggle their way in.   This is starting to feel like an IQ test for me.  

John Suavecito wrote:Then I saw them in there again.  I decided to make small, stopper pieces of wood for every part of the corrugated steel door, and jammed them in there, so they couldn't wiggle their way in.   This is starting to feel like an IQ test for me.  

... and a test for the mice IQ too ;-)

Did I get it this time? I put out some rat and mouse traps, because I didn't hear or see anything.  The next morning? Three dead rats.  So I looked around and saw a credit card sized hole on the inside of the building. Could they be coming from under the shed? I set out more traps today. When I went in tonight, what did I find? Two more rats in the traps.  I'm going to have to take out a lot of supplies and search carefully for how they're getting in.

JohN S
PDX OR

The plot thickens........

After blocking the credit card sized hole on the inside of the shed, the next day, there were no critters in the traps. Success? Maybe.  

To be sure, I put out 2 slices of apple and 2 pieces of sunchoke/Jerusalem artichoke. Their teeth can't make an impression like a knife slice, so I will have some data.

The next day, what did I find?  One slice of apple, completely gone, the other untouched.  One piece of sunchoke gone, the other untouched. And one rat trap untouched, the other, with a dead rat in it.  Hmmm.  Was there one left over rat, or are they still coming in more cautiously?  The flow of rats is definitely decreasing.  I put the two used rat traps out in the rain, so they will be rinsed off and hopefully, not smell so much like dead rats.  I have been using peanut butter as bait.  Should I change baits? My son said that we caught a rat in July.  We left an untouched trap with peanut butter in it for months, and it just caught a rat 3 days ago.  Maybe peanut butter has a longer staying power than other baits.  

I will keep you informed. Any advice is welcome.

John S
PDX OR

More data: They did not take the sunchoke.  They left both of them, so I wouldn't recommend using it as bait. They don't like it much.  They took the other apple slice. Completely gone. No tooth marks, nothing.  

My wife decided to hire a pest contractor for the attic.  They would add bait for the tool shed for a minimal fee, so I decided to do as much as I can before they get here.  I pulled out the bicycles and some boxes. She had mentioned that our dog sniffs around the drawers on one side.  The drawers were closed while the last rat was caught, so the rats are not coming through the drawers.  After pulling out the boxes, I think I see why the dog sniffs around the drawers.  Behind the drawers, there was a gap around the corner. It was only 2 1/2 inches wide (6 cm?), but that is plenty big enough for rats to get through.  I had to use a little creativity to block it off.  Different sizes of wood, hammered in, so the rats won't just push it out.  I got it all blocked off and nailed in right before the pest guys got here to bait them.  

Now I"ll await more data.

John S
PDX OR

Rebecca Fussner wrote:I have found that building a shallow planter for containment of mint around the shed keeps most critters out. My last one was about a foot wide and 6 inches deep on top of pavers {to keep the mints in) and planted my mint collection. Don't forget to mulch it.  For the door sill a line of salt with mint oil will keep it rodent free.

Mint’s good to fool them for a bit.  
But, in our decades of experience, & from some literature read long ago,
Pennyroyal contains elements that stop pests from reproducing, which other mints lack, or have too little of.  

I make a quart spray bottle filled with water, add about 1/2 to 1 Oz Pennyroyal oil + 1 to 2 drops liquid dish soap, & mist that on baseboard near floor, backs or undersides of cabinets, or in garage, or pantry areas.  
Pests know they should avoid mint smells—that’s the cue alert to them, but if they figure out it’s “just mint”, they ignore it & maraud anyway.

Pennyroyal groundcover plants, growing around the foundations of a shed or house, can do a pretty good job of repelling them away from the building.   They are fairly drought-tolerant in shade; maybe water every week or two, once established well. Little blue flowers, seasonally, & will come back from roots or seeds, if conditions are right.
The sides of the foundations I can plant them, did fizzle tho….even in our more humid climate, they needed watering more than I remembered to do.   But, eventually, I’ll replant, once there’s a moisture source on that side.

Cool idea.  Is birth control immoral if it is only for pests?:)

John S
PDX OR

Chi Monger wrote:...Pennyroyal contains elements that stop pests from reproducing, which other mints lack, or have too little of...  

Chi a quick search suggests there's two versions of plants called Pennyroyal - Northern European and North American.

"Mentha pulegium, commonly (European) pennyroyal, or pennyrile, also called mosquito plant[1] and pudding grass,[2] is a species of flowering plant in the mint family, Lamiaceae, native to Europe, North Africa, and the Middle East.[3] Crushed pennyroyal leaves emit a very strong fragrance similar to spearmint. Pennyroyal is a traditional folk remedy, emmenagogue, abortifacient, and culinary herb, but is toxic to the liver and has caused some deaths.[4] European pennyroyal is related to an American species, Hedeoma pulegioides. Though they differ in genera, they share similar chemical properties.[5]"
https://en.wikipedia.org/wiki/Mentha_pulegium

I have an area where establishing plants could be very helpful. It sounds as if both/either will do the job, but do you have any idea which one is used to make the oil you mentioned?

I can't believe it! After the last repairs to close off the last hole, I went in to check. No rats caught.  This was after leaving the traps out with peanut butter to attract the rats, but not setting them.  Then they were set and they still didn't come.   Just as a precaution, for a day or two days later, I set out perfectly cut slices of apple, which they devoured before.  This time? They weren't moved at all.  I think I'm going to call this a success.  I moved my storage apples from the much warmer attached garage to the tool shed again now that they seem safe.  Now they will last longer than they would have in the garage.  It still won't be as good as a normal year, but next year, I can start with an impermeable fort, so I'll store my apples a lot longer. Supposedly. :)

John S
PDX OR

Good posts here, and an issue here for several years at my place.

I keep all my seeds and most food in glass jars, metal tins (like you can get popcorn or coffee in) and some of those small metal "garbage" cans w/lids found at Rural King.

If on a FLAT floor, certain filing cabinets are mouse proof...too bad mine was on a very crooked wooden floor for a bit :)

Clean clean clean, sweep sweep sweep, and move furniture/shelves/crates/etc, often...open and check drawers for signs of food hoarding or bedding.

Looks like you are already trying your best to seal things up!

Heres a story, it's sad so don't read if you love mice :(

I do love mice, but I can also be shifty and turn to hate mice when suffering from insomnia due to thier ruckus. I'm not a fan of snap or sticky traps, if I'm going to kill something I want it to be personal. I've tried "friendly" traps in the past but sadly have forgotten to check them quick enuf and thats a bad thought to live with. My brother came down to stay for a bit and while I was kinda just dealing with the mice thru non-violence, he wasn't having it.

So I opted for a bb gun. Red Ryder to be exact. We ziptied a small flashlight to the barrel for nite stalking and I also had a flashlight (e have no electric here). Thought this would be a quick way to do the dirty work.

My brother took the first shot around 11pm... well it sent the poor mouse flying off the shelf but he ran away - we were on him tho and found him in a corner, another shot, ran again under the wood stove, 2 more shots nearly point blank...he was hurt bad but managed to scurry under a dresser. Another shot, I was holding my flashlight right on him up close, he took the hit, still alive, albeit slightly different looking and such a horrible look in his little eyes staring right at me from only 1ft away, I took the knife I had in my hand and had to let out a grunt and finished him aggressively with a thrust to the neck as hard as I could up against the wall. Wow, super traumatic I'll remember that mouse forever. I feel so bad but it definitely improved human living conditions here as that mouse was getting very bold due to the slack I had been cutting him. I gave him a proper burial outside, a real trooper.

Get this tho- 2 days later what appeared to be a female and 3 young were dead in my makeshift sink that I happened to forget to fling outside (think stainless steel bucket with acouple inches of water in it) I think they might have killed themselves out of missing or possibly witnessing the death of thier male father/partner?? I think about them nearly every day, this was about a month ago...a stray mouse or 2 have come in since then but not nearly as bad as the one I ended up killing.

I do know that I never want to kill another mouse again, just gotta do better at living clean and kept!

In summary, yes I basically live in a storage shed, and if you try to kill mice with a bb gun don't use a Red Ryder I'd say get something at least double the power like 650+ fps.

Some interesting thoughts and attempts on this thread. We have mouse plagues here. We do our best in this part of Australia to deal with them using the best ideas from people with lots of experience and from our own failed attempts in the past. Our last plague was three years ago. We were warned it was coming and did our best to prepare- removing stuff they could live in or under, blocking holes, putting valuables in containers of all kinds, etc., etc. The end result was that at the peak of the plague we trapped over one thousand mice INSIDE OUR HOUSE in five weeks. There were miles of road with squashed mice just inches apart. The pile of clothing, bedding and furniture at the local tip would have filled several semi trailers.
Cats eat a few and may help if you only have the occasional mouse near your home, but cats in Australia also kill one point five billion native mammals, birds, reptiles and frogs and one point one billion invertebrates annually. I kill every cat I can get in my sights. Most cats will play with the first rat they catch, get bitten and never touch another rat as long as they live. Rats can jump several feet and are excellent climbers. A friend of mine stopped them getting into the grain shed by building it out of stone and concrete and having a steel flange a foot wide angled down at forty five degrees embedded into the wall all the way around about three feet from the top. I built a feed shed for my cow feed out of corrugated iron sheeting and went to a lot of trouble sealing up anywhere around the floor and door the rats might try to get in. One week later I found fresh rat droppings in the shed. They were climbing a gum tree several feet away and jumping across to the roof. Rats and mice don't like cheese. They eat it if they're really hungry. Rats like the same stuff we like, so when you finish your yummy baked dinner, wipe the plate with a little piece of fresh bread and use that to bait your traps. If you see a rat running in your shed take note of the path it took- they leave a scent trail that they and other rats will follow. I set old weak rabbit traps on the trails- no bait. If the rat is cagey just drop a piece of old rag over the trap. For mice a good one is just a plastic bucket with a few inches of water in it and an empty aluminium drink can rotating on a stick set in holes at the top. Smear peanut butter or some other nut spread on the middle of the can. Put a couple of bits of board against the bucket as ramps. Oh yeah- chooks eat mice.