Hearing scratching in your garage at night is one of those sounds you really don’t want to investigate.
Then you find the droppings.
Then you start wondering whether that bag of bird seed you forgot in the corner has been hosting a tiny all you can eat buffet.
Rats are good at finding warm, quiet places with food nearby. Garages often tick all the boxes. Boxes, clutter, garbage, pet food, bird seed, garden supplies and a door that doesn’t quite seal can give a rat everything it needs.
The good news? A rat in the garage can be dealt with. The trick is figuring out how it got in and removing the reason it wanted to stay.
First, make sure it’s actually a rat
Rat droppings are usually much larger than mouse droppings.
Norway rat droppings are around 15 to 20 mm long and have blunt ends. Roof rat droppings are generally around 10 to 15 mm long with more pointed ends. Mice leave much smaller droppings, usually around 4 to 7 mm long. Still not sure? Here’s how to tell if you have mice or rats.
You may also find:
- Gnaw marks on boxes, wood, plastic or wiring
- Shredded paper or insulation used for nesting
- Greasy marks along walls or other places rats regularly travel
- A strong urine smell
- Food or garbage that has been chewed into
- Scratching or movement at night
And you don’t always have to see the rat.
Rats are usually much better at hiding than we are at finding them.
Why are rats getting into your garage?
Usually, it comes down to three things:
Food. Water. Shelter.
A garage can provide all three.
A bag of bird seed, pet food, garbage, spilled grass seed or even food waste in an open container can attract rodents. Leaking pipes and other moisture sources can help too. Clutter gives them somewhere to hide and build a nest.
The other problem is the garage itself.
Look closely around the garage door, corners, vents, pipes, foundation and places where cables or other services enter the building. In BC, the provincial guidance recommends sealing openings larger than about 6 mm, or 1/4 inch, with durable materials.
Yes, that’s a surprisingly small hole.
A garage door that looks sealed from six feet away can still have a gap at the bottom or sides that gives a rat a way in.
How to get rid of a rat in your garage
1. Remove the food
Start by making the garage boring.
Move pet food, bird seed, grass seed and other food into solid containers with tight fitting lids. Clean up spills and get rid of garbage that could provide food.
Don’t assume a cardboard bag is good enough. Rats can chew through plenty of things we’d consider perfectly secure.
2. Reduce clutter
Look behind stored boxes, lumber, old furniture and gardening supplies.
Rats like areas where they can stay hidden and move around without being disturbed. Clearing some of that clutter makes it easier to spot activity and removes potential nesting spots. Health Canada and the Province of BC both recommend reducing clutter and debris around garages and buildings.
You don’t need to turn the garage into a showroom.
Just don’t give the rat a private apartment behind six years of Christmas decorations.
3. Use rat traps in the right place
Snap traps are one of the main tools for controlling rats.
Placement matters more than most people think.
Rats tend to travel along walls and edges rather than wandering around the middle of an open garage. Put traps where you’ve seen droppings, gnaw marks or other signs of activity, and keep them somewhere children and pets can’t reach.
Rats can also be cautious around new objects. If a rat keeps ignoring a trap, pre baiting it can help. That means putting bait on an unset trap for a few days so the rat gets comfortable feeding there before you set it.
Peanut butter mixed with oats, dried fruit and other suitable food baits are commonly recommended for rat traps.
4. Don’t rely on ultrasonic rat repellers
Those plug in ultrasonic devices sound pretty appealing. Plug it in, press a button and supposedly the rat packs its bags.
Unfortunately, they aren’t a reliable long term way to get rid of rodents. HealthLink BC notes that ultrasonic repellers may appear effective at first but don’t provide lasting control.
So if your garage rat is sitting beside one looking completely unbothered, there’s a reason.
5. Find the entry point
Catching the rat deals with the rat that’s already there.
It doesn’t stop the next one from getting in.
This is where a proper inspection matters.
Check around the garage door seal, foundation, vents, pipe penetrations, utility lines, wall joints and any damaged areas. Use durable materials suited to the opening, such as metal mesh, hardware cloth, sheet metal or other rodent resistant materials.
Spray foam by itself isn’t always a great answer. Rats can chew through many soft materials, so the repair needs to stand up to a determined rodent.
What about rat poison?
This is where things get a bit more complicated.
Rodenticides can pose a risk to children, pets and wildlife. In BC, the use of second generation anticoagulant rodenticides is restricted to essential services, so homeowners should not assume every commercial rat bait they see is something they can legally use.
There is also the rather unpleasant problem of a poisoned rat dying somewhere you can’t reach.
Inside a wall.
Under a cabinet.
Behind the garage fridge.
You get the idea.
For many garage infestations, trapping and exclusion are a more straightforward starting point.
Don’t sweep up rat droppings
This one catches people out.
If you find rat droppings in the garage, don’t grab the broom or shop vac and go to town.
Rodent urine, droppings and nesting material can carry infectious material, and sweeping or vacuuming dry waste can put contaminated particles into the air. HealthLink BC and the CDC recommend wetting the material with disinfectant and wiping it up rather than sweeping or vacuuming it.
Wear gloves and follow proper disinfection and disposal procedures.
If the garage has a large amount of droppings, nesting material or contaminated insulation, getting professional help is a sensible move.
What if you catch one rat but still see droppings?
Keep looking.
One rat doesn’t necessarily mean there’s only one rat.
The CDC recommends continuing to trap until there are no more signs of activity. If fresh droppings, urine marks or gnawing continue, there may still be rodents present.
This is also why simply catching the rat you happened to see isn’t the whole job.
You need to know where it was travelling, what attracted it to the garage and how it got inside in the first place. For a bigger-picture plan, see our guide on how to get rid of rats permanently.
When should you call a pest control company?
DIY trapping can work when the problem is small and you know where the rat is travelling.
Call a professional when:
- You keep seeing fresh droppings after setting traps
- You’re hearing rats inside the walls or ceiling
- You can’t find where they’re getting in
- There’s a lot of droppings or nesting material
- The garage connects directly to your home (see rats in the basement)
- Rats have damaged wiring, insulation or other building materials
- You want to deal with the cause instead of repeatedly catching rats
A good rat control service should involve more than dropping off a few traps.
The inspection is a big part of the job.
The goal is to identify the entry points and conditions that are allowing rats onto the property, control the rodents that are already there and reduce the chance of the problem coming straight back. This approach lines up with BC’s integrated pest management guidance, which puts prevention and exclusion at the centre of rodent control.
How to keep rats out of your garage
Once the rat problem is under control, keep the garage hard to get into and boring to live in.
Seal gaps around the garage door and building.
Store food, seed and pet food in sealed containers.
Keep garbage closed.
Clean up spills.
Fix leaks.
Reduce piles of clutter and materials where rodents can hide.
And check the outside of the garage too. Rats don’t magically appear inside. There is usually a reason they were able to get close to the building in the first place.
Got a rat in the garage?
If you’re finding droppings, hearing scratching or you’ve spotted a rat running along the garage wall at night, don’t ignore it and hope it moves on.
It may.
It may also decide the garage is a pretty good place to live.
A proper inspection can identify where the rat is getting in, what is attracting it and what needs to be done to stop the problem from repeating.
At Westside Pest Control, we can inspect the garage, identify the source of the activity and put a plan in place to get the rats out and help keep them out.