Discovering you have a rat in the house can instantly send you into panic mode. It’s understandable since the word ‘rat’ is often synonymous with filth and unsanitary conditions. Unfortunately, rats can infest even the cleanest of homes if they offer easy access to warmth and shelter.
Fortunately, rats’ and other rodents’ noses are hypersensitive and you can use that to your advantage. Their sense of smell can either lead them to food or alert them to danger.
Rats find the smell of eucalyptus to be repulsive so you can easily use it to repel them away from your home!
But how can something that smells pleasant to (most) humans smell foul to rats? I mean rats do like to hang out in sewers and dumpsters but still. Keep reading to learn all about why eucalyptus repels rats and how you can use it to protect your home.
Why Does Eucalyptus Repel Rats?
Plants have evolved many different defenses to keep all sorts of organisms from harming them. This makes sense because trees can’t move or run away. These defenses can be obvious like thorns or more subtle like the production of chemical compounds that smell or taste bad to would-be predators.
There are more than 700 species of Eucalyptus. Its unique chemical compounds have been studied for centuries. It is used extensively in foods, perfumes, and even has pharmaceutical uses!
The biological properties of eucalyptus oil make it useful as an antimicrobial, fungicide, herbicide, insecticide, miticide, and nematicide. As a rodenticide, researchers aren’t exactly sure which eucalyptus compound specifically deters rodents. However, it has been noted that eucalyptol (1,8-cineole) seems to be the most important compound regarding its repellency.
While scientists don’t know exactly why eucalyptus repels rats, I’m just glad that it does!
How To Use Eucalyptus To Deter Rats
When it comes to using eucalyptus to repel rats, the plants’ oils are the real star of the show. While the entire tree contains eucalyptol, it isn’t really feasible or practical to use the leaves or bark as a rat repellent. Plus, the oils have the highest concentration of eucalyptol making them the most effective against rodents.
Below are the two most effective, research-based ways you can use eucalyptus to keep rats from coming into your home.
Just to add, if you’d like to use a different smell other than eucalyptus, take a peak at our full list of 15 Scents That Rats Hate for some more options!
Where To Use Eucalyptus To Keep Rats Out
Before you get started applying your eucalyptus repellent, you need to know where to put it to keep rats out. Rats can squeeze through any opening bigger than 1/2 inch!
Even if the opening is smaller, rats won’t hesitate to use their teeth to make it bigger. They will chew their way through just about anything to get where they want to go.
You’ll want to carefully check around the outside of your home for any small holes rats might use to get in. These are the places you’ll want to apply repellent to keep rats out.
Check around windows, doors, and places where your utilities enter the house. Don’t forget to look up to search for access points as well. Roof rats like to climb and will utilize openings around your roof line to get into the attic.
Differences Between Most Common House Rodents
|COMMON NAME||WHERE THEY HIDE||PHYSICAL CHARACTERISTICS|
|Norway rat||Burrowers, typically stay close to the ground in basements, crawl spaces, or the first floor||Around 13 to 18 inches long including the tail, tail shorter than the body, blunt snout, hairless tail, brown coat, droppings about 3/4 inch long with blunt ends|
|Roof rat||Climbers, typically found in attics, drop ceilings, or walls||Around 13 to 18 inches long including the tail, tail longer than the body, blunt snout, hairless tail, black coat, droppings about 1/2 long with pointed ends|
|House mouse||Climbers, can be found hiding anywhere in the house but prefers enclosed, cluttered areas||Around 7.5 inches long including the tail, pointed snout, tail slightly hairy, droppings about 1/4 inch long with pointed ends|
Here are a few of the most common rats in your house and where they like to hang out so you know the most likely places to find them.
Use Eucalyptus Essential Oils
Eucalyptus essential oils are easy to find because they have so many uses. Since they’ve become so popular, they’re also relatively cheap which I consider to be an added bonus!
Researchers have proven that eucalyptus essential oils are highly repellent to rats. They placed a bowl of food in a chamber sprayed with eucalyptus oil and released a rat. The eucalyptus oil alone was able to deter the rat from eating the food.
Eucalyptus oils are best used when made into a spray for repelling rats. All you need to create your own rat repellent is eucalyptus oil, rubbing alcohol, water, and a spray bottle. It doesn’t get much easier than that!
In a feeding study on rats, sprays made with as little as 5% eucalyptus essential oil were found to be effective. That’s the concentration you want to aim for with your homemade repellent.
Eucalyptus Oil Rat Repellent Recipe
Mix 2 tablespoons of eucalyptus essential oil with 2 tablespoons of rubbing alcohol in your spray bottle and mix thoroughly. As you probably know, oil and water don’t get along very well. By mixing the eucalyptus oil with isopropyl alcohol, you emulsify it which allows it to mix with water.
Next, add 2 and 1/3 cups of water to the spray bottle. Shake the mixture together and voila, you’ve got yourself an effective rat repellent! Now you can simply spray your rat repeller anywhere rats might try to sneak in.
This 100% Eucalyptus Essential Oil works great for making your own rat repellent! Since it’s not diluted, you can follow our recipe for making rat repellent without doing any math. This bottle will make about 10 cups of rat repellent using the above recipe.
The downside to using this method is how often you have to respray it. As the solution dries, the smell will diminish in a matter of days. You’ll likely have to reapply it at least twice a week or more.
You’ll also have to reapply the spray if it rains which will wash it all away.
If you prefer an option that doesn’t require as much continuous effort on your part, using eucalyptus wax melts may be a better option.
Eucalyptus Wax Melts Keep Rats At Bay
In 2017, a group of researchers decided to incorporate eucalyptus oil into wax blocks to repel rats. They hoped the wax blocks would work longer and require less effort when using eucalyptus against rats. Sure enough, they found that the wax prolonged the efficacy of the eucalyptus oil.
Luckily for us, eucalyptus has become so popular, you can easily find ready-made wax products which contain eucalyptus oil. The best option we know of is eucalyptus wax melts which you can find both online and at local retailers.
Try these Eucalyptus Leaf Wax Melts which are infused with eucalyptus essential oils. They have a strong scent and you get six cubes per pack. Feel free to cut each cube in half to get more bang for your buck.
Once you have your wax cubes in hand, all you have to do is place them anywhere you need to keep rats away from.
How Long Will Eucalyptus Work Against Rats?
Depending on what type of eucalyptus repellent you use, oil spray or oil-infused wax, it doesn’t last forever. Scents fade over time and eucalyptus oil is no exception. The mist will only last a few days and the wax only a couple of weeks.
Even though these products aren’t expensive upfront if you try to use them long term the cost goes up. Not only will you have to keep buying eucalyptus oil products, but you’ll also have to keep spending time applying them.
Let’s face it, time is money so the long-term cost of repellents can really add up.
While repellent scents are a great short-term solution to keep rats out, they work best when paired with exclusion methods. Using exclusion against rats is definitely a more long-term solution, especially if you’ve dealt with rats in your home before.
How To Exclude Rats From Your Home
As we mentioned earlier, rats can squeeze their way through holes with 1/2 inch diameter. That’s smaller than the diameter of a dime which is crazy! They’ll also use their teeth to make a smaller hole bigger if they need to.
To keep rats from getting into your home permanently, you need to seal up any holes that they may use to gain entry. But wait, how do you seal up a hole when rats can check through wood and even plastic?
Metal is the best way to keep rats from chewing their way in. We suggest using hardware cloth that has holes no bigger than 1/4 of an inch. Using mesh with holes no bigger than 1/4 inch will keep mice out too.
Covering holes that are up high around your roof is important but can be a difficult task. This is especially true if you live in a two-story home or condo.
If you find yourself in over your head, consider hiring a pest control professional to do the job for you. Most pest control companies will come out and seal up gaps and cracks for you to prevent pests from getting inside. Check out our pest control locator to find a professional near you!
Other Pests That Hate Eucalyptus
Rats aren’t the only organism that doesn’t want to be around eucalyptus. Researchers have found a wide variety of other pesticide uses for eucalyptus.
It can be used against certain insects, fungi, and even weeds. Current results are promising regarding the use of eucalyptus as a pesticide. However, we’re still a ways away from developing products that homeowners can use.
As concerns about the impacts of synthetic pesticides on the environment continue to grow, more funding is being given to researchers to develop organic plant-based pesticides.
Many Insects Can’t Stand Eucalyptus
As organic pesticides have become more popular in recent decades, more research has focused on using plant oils to manage insect pests. Eucalyptus has been shown to be effective in managing a variety of insect pests.
Pests that don’t tolerate eucalyptus well include mosquitos, beetles, flies, and moths. Certain insects are only affected by eucalyptus when they are immature while others are more susceptible to it as adults. Some insects are more vulnerable to specific species of eucalyptus plants.
Research regarding how eucalyptus might be useful as an insecticide is ongoing. As more research is conducted, we may eventually have a commercially available eucalyptus insecticide we can use.
Fungi Don’t Like Eucalyptus Either
Scientists have known about the fungicidal properties of eucalyptus for quite some time. Several studies have shown it is useful in getting rid of a variety of fungi that cause diseases in plants. They seem to work by preventing fungi to produce spores for reproduction or by preventing germination.
Some of the fungi that eucalyptus can control include Botrytis, Fusarium, Phythoptera, Pythium, and Rhizoctonia. While there aren’t any commercially available eucalyptus-based fungicides yet, you may see them show up in the near future.
Some Weeds Can Be Controlled Using Eucalyptus
You might find it surprising that the oil from one plant can be used against another plant. But eucalyptus oil can be used as an herbicide against certain plants. It’s better for the environment than traditional pesticides and can work just as well!
Here are just a few of the plants that don’t tolerate eucalyptus well:
- Bermuda grass
- Coffee senna
- Common purslane
- Italian ryegrass
- Littleseed canarygrass
- Mat amaranth
- Santa Maria feverfew
- Silverleaf nightshade
- Smooth pigweed
- White goosefoot
The use of eucalyptus as an herbicide still needs a ton of research. Scientists don’t fully understand how it works. They also don’t have a full list of all of the plants that can be negatively impacted by it. Don’t go spraying eucalyptus around your yard or you might damage plants you want to keep.
For instance, some desirable plants like Bermuda grass are negatively impacted by eucalyptus. So it wouldn’t be a good idea to use eucalyptus for weed control on your Bermuda grass lawn.
Combine Other Scents With Eucalyptus To Repel Rats
Eucalyptus isn’t the only plant that can be used to keep rats away. There are quite a few other options available out there that work just as well.
Here’s a few of the most common scents that can repel rats:
In fact, most of the commercially available products for repelling rodents combine several scents together – so do some research if you’d like to make your own specific rat repelling scent!
Rats can also become desensitized to certain smells over time. Having a variety of scents you can use will allow you to switch it up from time to time if you want.
Below is a table with just a few of the other plant scents rats hate. It also lists the repellent compound found in each of these plants that deter rats.
In case making your own repellent doesn’t interest you, we’ve also listed a few products for each plant in the table you can purchase and use. Just make sure you read and follow the directions carefully.
|Plant||Repellent Compound||Other Uses||Rat Repellent Products|
|Cayenne Pepper||Capsaicin||Insecticide||Home & Garden Rodent Mace|
|Garlic||Allicin||Insecticide||Tomcat Rodent Repellent|
|Peppermint, Spearmint, Wintergreen||Menthol||Insecticide | Miticide||Rodent Sheriff Pest Control Spray|
|Cloves||Eugenol||Fungicide | Herbicide | Insecticide||Bonide Rat Magic Rodent Repellent|
That’s A Wrap!
Rats can be a big problem in and around your home. Not only can they carry around some pretty nasty stuff but they can also chew through wood, plastic, and even electrical wires!
You can’t really use eucalyptus to get rats out of your house if they’ve already gotten in. You’ll have to use trapping or other methods if rats have already made it inside.
While eucalyptus can’t get rats out of your house, it can make them think twice about coming inside in the first place. Research has shown that eucalyptus can be used as an effective repellent against rats.
You can create your own rat repellent using eucalyptus oil but you’ll have to reapply it every few days. Alternatively, consider using eucalyptus wax melts which will hold up a little longer.
Remember, repellents shouldn’t be thought of as a permanent solution to keep rats out. You should pair the use of repellents with other methods such as sealing up holes to exclude rats from your home.
Batish, D. R., Singh, H. P., Kohli, R. K., & Kaur, S. (2008). Eucalyptus essential oil as a natural pesticide. Forest ecology and management, 256(12), 2166-2174.
Danna, C., Cornara, L., Smeriglio, A., Trombetta, D., Amato, G., Aicardi, P., & Caputo, L. (2021). Eucalyptus gunnii and Eucalyptus pulverulenta ‘baby blue’essential oils as potential natural herbicides. Molecules, 26(21), 6749.
Sachdeva, S., & Singla, N. (2018). Antifeedant and repellent potential of alginate based microcapsules containing eucalyptus oil against house rat, Rattus rattus. J. Entomol. Zool. Stud, 6, 608-617.
Singla, N., & Kaur, R. (2017). Increasing efficacy of eucalyptus oil as repellent against Rattus rattus by controlled release through encapsulated wax blocks. Proceedings of the National Academy of Sciences, India Section B: Biological Sciences, 87, 1407-1413.
Singla, N., Thind, R. K., & Mahal, A. K. (2014). Potential of eucalyptus oil as repellent against house rat, Rattus rattus. The Scientific World Journal, 2014.
Zack is a Nature & Wildlife specialist based in Upstate, NY, and is the founder of his Tree Journey and Pest Pointers brands. He has a vast experience with nature while living and growing up on 50+ acres of fields, woodlands, and a freshwater bass pond. Zack has encountered many pest situations over the years and has spent his time maintaining and planting over 35 species of trees since his youth with his family on their property.
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