9 Scents That Pill Bugs Hate (And How To Use Them)

Adult Pill Bug Armadillidium vulgare crawl on moss green background at spring season - super macro

When pill bugs show up inside the house, these pests can quickly become a nuisance for homeowners. Whether you call them roly-polys, doodlebugs, or various other nicknames, pill bugs share a little-known trait you can naturally and harmlessly exploit to deter them using scents that pill bugs hate!

Pill bugs smell through their antennae to detect pheromones. Garlic, cinnamon, peppermint, oregano, vinegar, coffee grounds, chili pepper, and cayenne pepper can interrupt a pill bug’s sense of smell and mask scents that attract them, causing pill bugs to stay away from that area.

Hmmm…interesting, but how do I use these scents? Read on to find out more about what pill bugs hate and how to repel them! First though, let’s identify what the often misunderstood pill bug is after all.

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What Is A Pill Bug?

Despite what you may have been told, pill bugs are not insects. They are crustaceans identified as the species Armadillidium vulgare.

Sounds like an armadillo. Yes, and for good reason! While not related, both share a similarly segmented, armor-like shell. 

Pill bugs are related to other crustaceans, including shrimp, crabs, crayfish, and lobsters. Unlike their water-dwelling relatives, pill bugs are the only species of crustacean adapted to live entirely on land. In fact, they cannot even survive underwater.

Where Do Pill Bugs Live?

Since all crustaceans breathe through gills, pill bugs are extremely moisture-seeking creatures. Remaining on land, they must keep their gills moist at all times. Drying out for even short periods leads to certain death.

With a need for constant moisture, pill bugs are most commonly found around fallen rotting trees, loose bark, wet leaves, and other similar yard debris. They also love to gather under rocks, pavers, mulch, and other landscaping materials. 

Such damp shady locations are ideal for pill bugs because they provide a constant source of moisture hidden from the drying effects of direct sunlight. This explains why pill bugs are nearly always found somewhere in and around the foundations of most homes. 

Ah, so that’s how they get in… but where do they go from there?

Where Are Pill Bugs Found In My House?

The short answer? Wherever there is water.

Pill bugs are most likely to be spotted in basements, bathrooms, laundry rooms, and occasionally in the kitchen. These locations often provide the perfect combination of moisture and darkness where pill bugs thrive.

Whether finished or unfinished, there are many desirable places for pill bugs can live in basements. This is because of the simple law of gravity. Water flows downhill, and basements will collect and retain more total moisture than anywhere else in the house.

You may think the basement is dry if there aren’t any obvious drips or puddles of water. But even slightly damp ceilings, walls, and floors will provide enough moisture for pill bugs to thrive.

While pill bugs need constant moisture, they are also tiny creatures who need little to survive. Check areas in and around crawl space openings, sump pumps, and drains for pill bugs. 

It is not pleasant to think you might share a bathroom with pill bugs. Unfortunately, bathrooms frequently offer near-perfect conditions they find attractive. Consistent use of the shower or bathtub generates enough steam to keep many surfaces moist enough for pill bugs to survive. 

Problem areas in the bathroom often include baseboards and anyplace in and around the bottom of cabinets. If you have a shower in the basement, you will want to check where the walls meet the ceiling. Pill bugs typically enter the house through the foundation, so they can easily find their way to these areas of high moisture.   

Laundry rooms can also be quite inviting to pill bugs. After all, who doesn’t find themselves constantly running an extra load or two throughout the week?

Additional moisture in an already humid space could lure pill bugs to take up residence. To make matters worse, damp or wet clothes lying in hampers or on the floor can be especially appealing.

Houseplants are another common breeding ground for pill bugs. They love to hang out underneath potted plants where they find ample moisture and shade. Homeowners returning home with that “perfect plant” for an empty corner often unknowingly bring pill bugs along for the ride.

If you specifically have pill bugs in your houseplants, take a look at our guide: 11 Tips For Removing Pill Bugs In Potted Plants.

Before jumping into the 10 scents proven to repel pill bugs, there’s one question you might have…

Are Pill Bugs Bad?

Fortunately, the answer is no! Pill bugs are not dangerous or harmful to humans or pets at all. While they are unsightly and can be a nuisance, they pose no known risk to health or safety. 

Despite being harmless, if you are dealing with a true pill bug infestation, seek the help of a professional exterminator.

Without further ado, let’s talk about scents!

9 Scents That Pill Bugs Hate

Adult Pill Bug Armadillidium vulgare crawl on moss green background at spring season - super macro

So, the reason why scents work to repel pill bugs is because pill bugs use scents to travel. Yes, their sense of smell is somewhat limited. HOWEVER, their antennae which protrudes from their head is actually how they smell.

Here’s the kicker, the part of their antennae that can detect smell, also called the tactile setae, is what pill bugs use to search for food and the pheromones of other pill bugs.

The scents listed below, if used properly, will disrupt their scent trails and make pill bugs unable to find their desired food sources, which in turn will repel them.

Here are 10 scents that disrupt a pill bugs sense of smell and will repel them:

  • Garlic  
  • Cinnamon Oil
  • Peppermint Oil
  • Oregano Oil
  • Vinegar 
  • Coffee Grounds
  • Dead Pill Bugs
  • Chili Pepper Oil
  • Cayenne Pepper Sauce
  • Neem Oil

Let’s look at each scent and how to best use it. 

Garlic

Garlic produces a strong pungent odor when crushed. This causes a chemical reaction between substances inside and outside of its cell walls. Pill bugs and most insects will avoid the scent of garlic.

One downside? Many humans dislike the smell of garlic as well. As always, proper use is the key to using it successfully without chasing everyone away!

Mix one tablespoon of crushed garlic and one quart of water in a spray bottle. Remember that pill bugs have a much more powerful sense of smell than humans, so a little goes a long way. Lightly spray on already damp areas throughout the house.

The goal is to infuse the odor of garlic into areas of moisture already present in the house. This will create a chemical barrier, making such areas far less desirable to pill bugs even after they dry.

Cinnamon Oil

Cinnamon oil contains a large amount of cinnamaldehyde, a natural substance approved by the FDA for the food and flavoring industry. The scent deters pill bugs, as it has the potential to disrupt their ability to convert food into energy.

This one fluid ounce bottle of Ethereal Nature 100% Pure Oil, Cinnamon is a wonderful option. It can be used in diffusers, as a spray mixed with water, and in many other amazing ways.

The most effective way to use the scent of cinnamon oil is to make a homemade sachet. Take a piece of cloth or fabric (most any kind will do) and fashion it into something resembling a coin purse with a needle and thread. 

If sewing is not your cup of tea, consider these basic Cotton Muslin Bags are a great alternative. They are made of 100% cotton muslin in the USA.

Place 4-5 drops of cinnamon on a cotton ball, place it in a sachet, and store the sachet in any area where you wish to eliminate pill bugs. Less is best, but if you love the scent of cinnamon, use more oil or place more satchels around the home.

Peppermint Oil 

The same general principles of cinnamon oil apply to peppermint oil as well. While more research exists on the effectiveness of cinnamon oil, peppermint oil has also been observed to have similar effects on pill bugs and other pests.

The Ethereal Nature 100% Pure Oil, Peppermint could be the peppermint oil for you! It is perfect for use in aromatherapy and doubles as a pest repellent.

As there is likely little to no practical difference in terms of effectiveness, choosing the scent of peppermint over cinnamon boils down to preference.

Oregano Oil

Oregano oil bottle with label and oregano herb bunch

Oregano, a member of the Lamiaceae family of plants, is unique in how it works as a natural pesticide. Natural chemicals in oregano inhibit the egg-laying and larval development of insects. When made into an essential oil, these effects only increase.

This SVA Organics Oregano Essential Oil is a top choice for oregano oil. They are keen on customer satisfaction and offer a full refund if you are unhappy with your purchase in any way.

Female pill bugs reproduce by laying eggs into a marsupium (brood pouch), often up to 200 at a time. Wait, aren’t kangaroos and koalas marsupials? Why, yes, they are. Who knew pill bugs have such an unlikely connection?! 

While pill bugs are not insects, since they reproduce through laying eggs, oregano oil may play a role in decreasing their population. Unlike cinnamon and peppermint oil, oregano oil requires physical contact to be most effective.

Here is a recipe for a homemade oregano spray.

Ingredients:

  • 1 gallon of water
  • 1 quart of vinegar
  • 2 Tbsp biodegradable liquid soap
  • 4 drops oregano oil
  • 1 large bucket
  • 1 medium spray bottle

Directions:

Place a large bucket outside or in a large utility sink. Mix and stir all ingredients in the bucket until thoroughly blended. Carefully pour the mixture into the spray bottle until it is about three-fourths full. Discard the remaining contents of the bucket.

Lightly spray any suitable area where you have identified pill bugs. Check the results in 3-4 days. Repeat as needed. 

Please keep in mind that if you have a serious pill bug infestation, this probably won’t work. You should contact a professional if that’s the case.

Vinegar

If you wish to avoid garlic and essential oils, vinegar may be just the thing for you. Alternatively, you can use vinegar to supplement your use of other scents. 

Vinegar has a long history of success in trapping pill bugs along with a host of other insect pests. Simply pour a small amount into a shallow container and place where desired. While commonly used outside in the garden, there is no harm in using vinegar traps inside as well.

Simply check every few days, dispose of any collected pill bugs, and reset as needed. 

Of course, make sure you place them where they are unlikely to get knocked over by kids or pets!

Coffee Grounds

For those who love the smell of coffee, placing shallow bowls full of regular or burnt coffee grounds near an area containing pill bugs will act as a potent deterrent. 

As a bonus, the caffeine in coffee grounds is also quite effective in repelling ants. If you have problems with both pests, coffee grounds offer a unique 2-for-1 advantage!

Pill Bug Remains

Remember from earlier how pill bugs use their sense of smell to communicate with each other? Well, it turns out that pill bugs are extremely sensitive to the odor of those fellow members of the species who have passed.

The fatty acids of the dearly departed emit a strong chemical signal that naturally repels the living members of the species. The good news? This scent is virtually undetectable to humans. Whew, right?

The bad news? Researchers have found the most effective method to deter unwanted pests in such cases is to crush them up and spread around what they describe in highly technical terms as the “juices.”

As gross as this is, it makes a whole lot of sense.

Chili Pepper Oil / Cayenne Pepper Sauce

These two scents go together in the “turn up the heat” category. Insects share a strong dislike of spicy scents like chili pepper oil and cayenne pepper sauce. Although pill bugs are not insects, they share the same opinion.

Chili pepper oil like the Gya Labs Chili Essential Oil is a prime example of what to use. Not only is it great for repelling pests, but they also claim it can dull aches and pains.

A word of caution: these substances have the potential to be harsh on sensitive noses and eyes. For some, tears may form at the mere thought of using either scent in the home. 

While you can use them in cotton ball sachets like cinnamon and peppermint oil, chili pepper oil and cayenne pepper sauce may be better suited for outdoor applications.

To make an effective outdoor spray, you can easily substitute chili pepper oil for oregano oil in the previously outlined recipe.

Neem Oil 

Neem oil is a natural substance found in high concentration in the seeds of the tree Azadirachta indica, a South Asian and Indian plant commonly used as an ornamental shade tree. It has been used in wax, oil, and soap preparations for centuries. 

Neem oil is a strong repellent of pill bugs and most insects because of its powerful scent. Specially formulated for organic gardening and houseplants, it can be another tool for dealing with unwanted pill bugs in those specific applications.

There are ready-made sprays like the Natria 706250A Neem Oil Spray if you go the neem oil route. As stated above, neem is a popular repellent for many pests, and this spray claims to help with fungal growth as well.

While using scents can certainly help eliminate unwelcome pill bugs from the home, your efforts will be most effective in combination with a broader prevention plan. 

Let’s review some important steps you can take both inside and outside your home to address issues with pill bugs.  

Tips For Repelling Pill Bugs Indoors 

small black isopod pill bug on palm of hand.

Along with using scents to repel pill bugs inside the home, here are other general tips you can use throughout your pest repelling journey.

Lower The Humidity

Since pill bugs cannot survive without moisture, one of the most effective preventative steps you can take inside the home is to decrease humidity wherever possible. 

If you have a basement, a dehumidifier is virtually a must. While it will probably always be the most humid place in the house, keeping the overall humidity down can only help your efforts to banish pill bugs. 

Make sure the stove hood vent, dryer vent, and bathroom fans are all in good working order. Fix any minor problems before they get larger.

Properly Seal Doors, Windows And Sills 

Poorly sealed doors can wreak havoc in your efforts to eliminate pill bugs and other pests. While obvious holes can invite mice and other small animals, the biggest concern with pill bugs is moisture.

After repairing any obvious signs of damage, check the weatherstripping on all exterior doors (do not forget the garage door). While it may be dry in fair weather, replace missing or worn-out pieces. These susceptible areas are sure to allow moisture to gather and persist. 

Go outside to check all basement and ground-floor windows for obvious signs of damage. Make repairs as needed. Carefully inspect around each window and sill for signs of moisture or rot. Few areas are more inviting to pill bugs than the underside of soggy or rotting wood.

Check all windows from inside the house to make sure they are dry and properly sealed. Make repairs as needed. 

Things You Can Do To Prevent Pill bugs In The First Place

Armadillidium vulgare sleepimg in the dirt

The best way to keep your home free of pill bugs and other pests is to prevent them from coming inside. Here are some practical tips to get you started.

Properly Secure Your Foundation

Making sure your foundation offers a strong physical barrier is a top priority for keeping pill bugs out. Use a caulking gun to seal up any visible cracks at or near ground level. 

Make sure the grading all around your foundation carries water away from the house. If you find areas where water either travels back toward the foundation or pools, you may have a problem. 

Throwing down an extra bag or two of dirt or mulch might help in the short term, but grading issues often require the help of a qualified professional.

Once you address any grading issues, check your gutters and downspouts to make sure they are in good working order. 

Maintain Proper Landscaping 

Walk the exterior perimeter of your house and check for any excess vegetation or natural/organic debris. 

Overgrown shrubs and other plants near your foundation will offer pill bugs constant shade and moisture, increasing the odds they might start turning up inside. 

Clear these areas yourself or hire a qualified professional for help.

If you use mulch around the foundation, keep it under 4 inches deep and never allow it to touch any finished wood on the side of the house.

Avoid excessive grass clippings, especially around the foundation. If you have an irrigation system, make sure all heads are pointed away from the house. Even an errant light mist near the foundation could encourage a pill bug breeding ground. Ditto for leaking hoses. 

Proper Waste Management

Finding pill bugs under trash bags, bins, and recycling containers is an unpleasant discovery many homeowners have or will experience at some point. Whether you store these materials inside or outdoors, they can trap water between the bottom surfaces and the ground, providing the dark damp conditions pill bugs love most.

The contents of the receptacles themselves often add to the problem. What better place for pill bugs to live than underneath that soggy pile of newspapers or cardboard you set out early to be picked up? 

Even worse, every time these receptacles are returned after their weekly pickup, they can offer pill bugs a free ride closer to the inside of your house.

Here are a few practical tips to reduce these potential pill bug problems:

  • Avoid placing any liquids in the trash. 
  • Avoid storing trash and recycling directly on the ground.
  • Avoid setting trash and recycling out too early.
  • Always check the bottom of each bin or container before returning.
  • Allow wet bins or containers to dry before returning.
  • Clean up any spills or messes promptly.

Practicing good waste management techniques will go a long way toward preventing pill bug problems inside the house.

Keep Firewood Dry

Always stack firewood off the ground and as far away from the house as possible. Cut wood often provides ideal conditions for pill bugs and other pests, so keeping stacks high and dry will help make sure they stay outside where they belong.

Maintain Proper Ventilation

Make sure areas you may not visit often, such as crawlspaces and attics, get regular ventilation. As moisture-seeking creatures, pill bugs will never take up residence where they don’t have a constant source of water.

Parting Thoughts

Pill bugs have a truly amazing sense of smell. Proper use of the 10 scents pill bugs hate can help repel and deter the ones already inside your house. These scents can also help with longer-term protection when used regularly.

However, using scents alone probably will not solve your pill bug problem entirely. They will be most effective as part of a broader prevention plan. 

Combined with other general preventative measures, scents can go a long way toward a comprehensive approach to getting rid of pill bugs and keeping them out for good!

References

Schotte, M. (2006). Roly-poly lifestyles. Wings-Essays on Invertebrate Conservation.

Nollet, L. M., & Rathore, H. S. (Eds.). (2017). Green pesticides handbook: Essential oils for pest control. CRC Press.

Koul, O., Walia, S., & Dhaliwal, G. S. (2008). Essential oils as green pesticides: potential and constraints. Biopesticides international4(1), 63-84.

Smigel, J. T., & Gibbs, A. G. (2008). Conglobation in the pill bug, Armadillidium vulgare, as a water conservation mechanism. Journal of Insect Science8(1).

Raham, G. (1986). Pill bug biology: A spider’s spinach, but a biologist’s delight. The American Biology Teacher48(1), 9-16.

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