There are several home remedies to help kill and repel mice, some more effective than others. One substance that comes up as a possible rodent deterrent is coffee. Since coffee is toxic to mice, some people think putting coffee beans out will drive them away.
Coffee beans will kill mice if they eat them because the levels of caffeine in the coffee beans are toxic to them. However, mice aren't interested in consuming coffee beans as food so it makes a poor rodent poison or bait. Coffee can be used to help absorb the smells associated with mice.
Coffee can be used to repel several kinds of pests around your home, but are mice actually vulnerable to it? Read on to learn more about whether coffee kills mice and how you can use coffee to deal with mice.
Will Coffee Beans Kill Mice?
Technically, coffee beans will kill mice. The bad news is that mice don't like to eat it, so it can't be used as a natural poison or deterrent against them. Coffee isn't reliable for repelling rodents like some other home remedies since some mice don't seem to mind the smell.
There's a few reasons coffee beans aren't tempting for mice:
- Coffee is strongly aromatic. The oils in coffee that allow you to smell it brewing from across the house make it an overpowering scent for mice. They won't eat something that smells so pungent. As prey animals, mice also tend to avoid any area with strong smells since these overpowering smells can make it difficult for the mice to smell predators.
- Raw coffee is very bitter. Coffee doesn't make a tempting bait for mice because it doesn't taste very good raw. While mice might be attracted to areas that store coffee beans, such as coffee shops, this is because they're attracted to any kind of shelter where bulk foods are stored for long periods.
The bad news is that these traits will make raw or roasted coffee beans one of the weakest baits you can use in a trap. They also don't smell strong enough in a whole state to act as a reliable deterrent.
What Happens When Mice Eat Coffee?
It's a good thing for mice that they don't like to eat coffee, because this caffeinated plant can be poisonous to them even in small amounts due to their small size. The same caffeine that humans drink coffee for to help them get up in the morning can cause negative symptoms in mice such as the following (Source: Conduct Science):
- Heightened anxiety: Mice are already a relatively hypervigilant animal since they are preyed on by pretty much every animal that is bigger than they are. Coffee can increase this anxiety to the point that the mouse can't perform routine tasks.
- Decreased locomotor activity: In lower doses, caffeine has been shown to increase locomotor activity in mice. In higher doses, it has been shown in scientific studies to have the opposite effect.
Because they aren't attracted to it as food, most mice in the wild will never ingest enough caffeine to have to deal with a toxic reaction to it. In large doses it would cause the same symptoms of caffeine overdose as it causes in people, such as tachycardia and death. (Source: MedicalNewsToday)
Do Mice Avoid Coffee Beans?
Coffee beans don't make an effective deterrent in their whole state. This is because their scent is much more mild in their whole form than the smell of coffee that has been freshly ground.
While coffee beans probably aren't enough to keep mice at bay, freshly-ground coffee can be used as a deterrent since it smells much stronger than whole coffee beans. In some cases, mice will avoid areas where fresh coffee grounds have been spread around since the strong smell is off-putting to them.
Used Coffee Grounds Don't Repel Mice
In case you were thinking about reusing used coffee grounds to repel mice rather than whole coffee beans, think again. Used coffee grounds are even less effective at repelling mice than fresh or roasted coffee since the smell is much more diluted in coffee grounds that have already been brewed.
How to Use Coffee on Mice
Even though coffee isn't an effective deterrent or poison bait for mice, you can still use it in your home to help deal with a mouse problem.
One of the biggest hassles in dealing with a mouse infestation is that if you use poison, mice have a bad habit of eating the poison, then crawling into the wall and dying. This can lead to a rancid, decaying smell of dead mouse that may linger in the area for days or even weeks depending on the humidity.
Freshly ground coffee can be laid out in bowls in areas where you have a lingering dead mouse smell, as the strong aromatic oils in coffee can help overwhelm and diffuse the smell without layering a bunch of perfume on top of it. (Source: HowToGetRidOf)
Using coffee and other odor killers in areas where you've had a dead mouse stuck in the wall can be a much easier solution than cutting a hole in your drywall to find the dead mouse and extract it. Eventually, the mouse's body will dry up and the smell will go away.
Rodent Deterrents Other Than Coffee
Coffee beans may not make a good deterrent against mice, but there are several other household items that you can use as an effective mice repellent. Here are a few other things you might find in your kitchen or pantry that can help you drive off house mice:
- Peppermint oil: Like ground coffee, mice find peppermint oil and other strong aromatic oils repellent because they cover up the smell of predators. You also have to keep in mind that as strong as these smells are to humans, they are much stronger to animals like mice that have a keener sense of smell than people.
- Cinnamon: Cinnamon is another strongly-scented spice you can find in your kitchen cupboards that will help you keep mice at bay. The advantage of using cinnamon as a mouse deterrent is that you can place it out as whole cinnamon sticks or cinnamon bark rather than ground cinnamon, which can be messy.
- Dryer sheets: The same perfumes that people love in dryer sheets are overwhelming for mice and other animals. An advantage of using dryer sheets to deter mice is that they can be easily tucked into small areas where mice might get, such as bookshelves or cupboards.
Even coffee beans are a poor deterrent for mice, there are plenty of other options around the house for you to use that can help you keep rodents away. These aromatic substances can also be used to help diffuse the smell of a dead mouse in the walls.
Coffee Beans Are Poor Bait for Mice
Coffee beans might technically kill a mouse in large enough doses, but good luck getting a mouse to eat that much coffee. Instead, use some of the household solutions suggested above to get rid of any mouse problem you might have.