Rodent-Proofing the Garage

Rodent Proofing the Garage

As the nights turn cooler, we tend to hunker down and add blankets to the beds, unearth knee rugs for watching our favourite shows and enjoy heartier meals. That is also true for rodents, who’ll be looking for warm places to nest and an ample supply of food. Ideal spots for rats and mice to take up residence in your home are roof cavities, wall spaces and in the garage. In this article, we identify signs of a rodent infestation and offer ways to create a rodent-free garage and home.

Identifying an Infestation

Look for these signs that will help you determine whether you have a current or previous rodent infestation in your home.


Sighting of the pest, its droppings or rodent nests

Certain signs can indicate the size of a population. If rodents are seen at night but never during the day, the population is probably small enough to be controlled with traps and bait. If you are seeing rodents during the day, numerous fresh droppings or new gnaw marks, it is likely that the population has become quite large and may require professional services.

Fresh droppings are dark and moist, as droppings age they dry out, becoming grey and crumbly. Droppings are most likely to be found near food packages, in drawers or cupboards, under sinks, in hidden areas, and along rodent runways. Rodents will use materials such as shredded paper, fabric, or dried plant matter to make their nests.

Gnaw marks and holes

In contrast to the droppings, newer gnaw marks will be lighter in colour and become darker as they age. These will often be found on food packaging or the structure of the house itself. The size of the marks can indicate whether you have rats or mice. If you previously had a mouse infestation, but are now seeing larger gnaw marks, it’s likely that you now have rats.


Scratching or scampering noises

More likely to be heard at night, when rats are at their most active.

Foul odour

Look out for unusual odours, like urine or a musky smell. If you see your pet pawing at an area in which it had previously had no interest, examine the area for rats or mice. If an infestation is large, you may also detect an ongoing stale smell coming from hidden areas, indicating an active infestation.

Prevention measures

Preventing rodents in a garage is largely a matter of denying nesting and hiding areas, eliminating food and water sources and blocking entry. Unfortunately, the reality is that vermin will usually find a way into a garage, so staying on top of prevention requires ongoing seasonal effort.

A clean, pest-free garage is the best place to start. It’s advisable to declutter your garage and keep on top of cleaning. NB. If you have a mouse and/or rat infestation, wear a face mask when sweeping in the garage, bacteria could be present and the dust may cause allergic reactions. 

Below Left, every rodent's dream garage; Right, Plastic bins are a great rodent-proof storage solution


Above, Keep outdoor areas free from bushes and structures that could be used to gain access by pests.

Outside, keep the landscaping around the foundation of your home free from brush and thick layers of mulch. Keep woodpiles away from the house if possible and use deterrents around wood stored indoors. Cover the rubbish bin at all times.

Keep food sealed or out of the garage, the same goes for pet food, fertilisers, seed and grains. Tightly sealed plastic containers are your best bet for keeping rodents at bay.

Block entry points

Rats can get through extremely small spaces! Carefully inspect concrete pathways and foundations, fill any cracks, holes, and crevices with concrete patch. Stuff wide cracks in wood walls with steel wool before patching to help prevent gnawing. Seal up any holes or cracks in your roof area with silicone caulk and make sure that all vents are properly screened.

Home Remedy Repellants

Please note that these repellant ideas may be effective at deterring or removing small rodent infestations. For large infestations, we recommend enlisting a professional pest eradicator.


Rodent repellant chemicals are available to purchase, but for a DIY rodent repellant, you can concoct a natural mixture that mice hate. Mix one tablespoon of hot chilli sauce (the hotter the better), and ¼ cup laundry detergent in a bucket of water. Spray it liberally without fear of harming children or pets.

Peppermint is a natural rodent deterrent that is environmentally safe. Spray a solution of peppermint extract and water around the perimeter once a week and after rainstorms. Dip some cotton balls in peppermint oil and spread them throughout rat-prone areas. If you don’t have peppermint oil, great alternatives are citronella oil and castor oil. Or, you can plant peppermint around the foundation of your home and garage to repel rodents. Note that while these oils can help deter rodents from entering your home they won’t do much to remove mice already living there.

Mothballs are poisonous to rats and mice, making them a good pest repellent. Place generous amounts of mothballs in your garage and roof cavity if you suspect rat presence. Please note, Mothballs are extremely toxic. NEVER place mothballs in an outdoor area or anywhere that children and pets are at risk of exposure.

The strong odour of Ammonia keeps rats away for good. In a bowl, mix a quarter of a cup of water, 2 cups of regular ammonia, and 2 tablespoons of detergent. Place the bowl in the infested area and let it do its magic.

For another eco-friendly solution, use an ultrasonic rodent repeller inside the garage or roof cavity. An ultrasonic repeller is inaudible to humans, but the sound it produces is very painful to rodents, they will not enter an area where this device is humming. 

Consider getting a pet cat. Most cats make short work of mice and rats and as long as they don’t bring them inside to show off, the job is done. 

Looking for tips for preventing pests of the human kind?

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