If you are dealing with rats, mice, squirrels, or other rodents tearing up your garden, pooping all over your attic, or eating the wires in your cars then trying to find a repellent for these creatures makes a lot of sense.
The problem is that there are a lot of different repellents for sale and some are not as good as others. It begs the question, “What are the best repellents for rats, mice, and other rodents?” I did a little research and want to share what I learned.
There are two classes of rodent repellents, Natural and Electronic. Overwhelmingly, the best repellents for rats, mice, and other rodents are the natural repellents based upon the chemicals found in balsam fir oil, mint, black pepper, red pepper, and other natural ingredients. Electronic repellents sometimes work in the short term but rodents quickly learn to ignore them.
Natural Repellents for Rats, Mice, and Rodents
The natural repellents work by different mechanisms from each other and sometimes it makes sense to combine two or more options. For example, some options, such as balsam fir oil and mint, create an odor that rats find unpleasant; this makes rodents want to stay away. Other options, such as pepper extracts and castor oil, are highly unpalatable and prevent rats and mice from chewing and eating whatever they are applied to.
By combining products that keep rodents away with a product that prevents rodents from chewing you greatly increase your chances of success.
Natural Repellents That Create Unpleasant Smells for Rodents (Keeps Rats Away)
Fresh Cab is a commercial product with the active ingredient being balsam fir oil. Balsam pine oil has been studied and registered with the EPA as a non-hazardous biochemical pesticide According to the EPA documentation, “Balsam fir oil repels rodents by emitting an odor that is offensive to rodents but not offensive to humans.”
Peppermint Oil is probably the most popular natural deterrent owing to its ease of use and pleasant smell. According to the New York State Integrated Pest Management Program and the Cornell Cooperative Extension, peppermint oil is a viable ingredient eligible for Minimum Risk Pesticide Use and has been shown to be effective in repelling rats.
Peppermint oil is available as a concentrated extract or as a pre-formulated spray.
Many repellents will also include some organosulfur compounds because they smell so unpleasant to humans. You will see these ingredients listed as “putrid eggs” and “extracts of garlic and cloves”. While it probably doesn’t hurt to include these compounds the reality is that they are unpleasant to humans but not necessarily to rodents. I have been unable to find a single scientific study that showed rodents were repelled by organosulfur compounds.
Another class of repellent that is based upon the rodent’s sense of smell is predator urine. The idea behind these products is that if a rodent smells the presence of something that wants to eat it then it will not want to be in the area. Seems simple enough!
Natural Repellents That Taste Bad to Rodents (Prevents Rats Chewing)
These deterrents are a little tricky since not all rodents have the same taste receptors.
Products based upon the chemicals found in spicy red peppers (Capsaicin) are highly effective at keeping squirrels from chewing on objects but will not deter rats or mice. As a reference point, here is a video showing rats comfortably eating the hottest peppers in the world.
Rats and mice are deterred by the chemicals found in black pepper (piperine) as that chemical is actually very toxic to them.
Another compound that will make rodents sick and they tend to avoid is castor oil. Castor oil, like mint, is a viable ingredient eligible for Minimum Risk Pesticide Use and has been shown to be effective in repelling rats
To account for these differences many of the taste-based repellents contain a combination of castor, red, and black pepper oils.
Electronic Repellents for Rats, Mice, and Other Rodents
Electronic rodent repellents work by emitting a high pitched ultrasonic noise that, when first encountered, is startling to rats and mice. The problem is that rats are smart and eventually learn that while the noise is annoying it is not harmful.
Since rodents figure these devices out so quickly, ultrasonic repellents have been the target of false advertising crackdowns by the Federal Trade Commission since 2001-2002. At this point, even industry advocates concede that rats will eventually become acclimated to the noise once they realize that it is harmless.
Ultrasonic repellents might help you out with a “quick fix” but if you use these then do not rely upon them ALONE to solve your infestation problem. For more information please read Do Ultrasonic Repellers Work On Mice?
Best Way To Use Repellents
The important thing to remember about any of these repellents is that everyone’s situation is different and something that solved one person’s problem may not solve yours. As you read the user reviews for the different products realize that just because product XZY was able to keep mice out of a car engine does not mean that it will be effective for keeping squirrels out of your attic.
The effectiveness of repellents based upon smell will diminish as the smell evaporates. These repellents must be reapplied on a regular frequency, either weekly or monthly, based upon label directions. Repellents based upon taste should be reapplied if the item they are protecting is exposed to rain, etc.
While many people report great success in getting rid of rats using repellents alone you will have the best long-term success if you use repellents as one part of an overall rodent control strategy. The use of traps and poison may be required to completely eliminate an existing infestation.
After your current infestation is dealt with make sure you seal up all of your garbage cans, throw away excess pet food and do anything else required to make your home less attractive.
Noah Thompson is an expert in rat relief, providing invaluable tips and advice on effective rat control. With extensive knowledge in rodent behavior, he simplifies complex concepts, empowering readers to confidently tackle rat infestations. Through workshops and seminars, Noah equips communities with practical skills while advocating for humane treatment and control of rats.