Are you looking for cockroach repellents? Then you’ve come to the right place.
In this Pest Strategies product review you can expect to learn:
- Cockroach biology and behavior
- What the various roach repellents are
- How well roach repellents work
- What to do with a cockroach repeller
- How to use them in combinations
- How to avoid common mistakes when using roach repellents
Ed has been working in the pest control industry for years helping 1,000's of homeowners navigate the world of insect and rodent management. He manages Pest Strategies now helping homeowners around the world!
What is the Cockroach’s Biology and Behavior?
Before you go to war with an enemy, it helps if you know something about them. With that in mind, we’re going to give you a brief run through on cockroach biology so you’ll better understand what you’re up against.
The German cockroach is the most common household pest today. PCO’s (Pest Control Operators) get more calls for roaches than almost anything else.
They carry asthma-inducing allergens and are a known vector for antibiotic-resistant bacteria. Roaches are small – the size of a dime or penny – and very fast. They’re usually tan or light brown with two black “racing stripes” down their back.
They prefer to live in tight spaces where they can feel something rubbing on their backs, which makes them feel protected from birds who are their natural predators.
If they don’t feel something on their backs it means they are exposed to the open sky and birds might eat them, so they prefer tight cracks and crevices as a safety measure.
Mature females produce 12-36 eggs at a time, and once hatched, the babies grow to adulthood in about 50-60 days. Temperatures warmer than 80ºF can shorten that time considerably.
They are nocturnal and can almost anything; spilled milk, old eggs, each other’s dead bodies (yes, they’re cannibals), cat poop; the list goes on and on, getting more disgusting all the time.
What Scents Repel Cockroaches?
There are some odors which naturally repel cockroaches along with other insects. Chief among them are chrysanthemum flowers, also known as garden mums, which have strong repellent properties.
They produce a natural chemical called pyrethrum, as a protection against invasive insects. Many insecticides use pyrethroids, an artificial version of pyrethrum, as their active ingredient.
Planting chrysanthemums around the house, keeping potted chrysanthemums in the kitchen is one way of repelling cockroaches. It would take quite a few of them, no more than a foot apart to create a barrier, but conceivably it could be done.
The following video will give you more tips in getting rid of cockroaches.
Do Essential Oils Repel Cockroaches?
The answer here is a definite maybe. There aren’t any published scientific studies on the effectiveness of essential oils on cockroaches, but anecdotal evidence is quite voluminous.
Many people claim, quite vociferously, that essential oils have eradicated their cockroach problem completely.
While anecdotal evidence isn’t scientifically rigorous, it is still evidence. Think of it as akin to eyewitness testimony in a criminal trial.
You can’t weigh testimony on a scale or measure it with a ruler, but it can send a person to jail or set them free, so it does matter. The same thing is true with “eyewitness testimony” about essential oils.
Some of the essential oils that have a lot of eyewitness testimony in their favor are peppermint oil, eucalyptus oil, and cedar.
Peppermint smells fresh and clean to humans, but for small creatures like insects, the odor is overpowering. It is too strong for them and they try to get away from it if they can.
Notice the word “try”.
They may not like the smell of peppermint but if they’re hungry enough, they’ll brave it anyway to get something to eat. The same principle applies to eucalyptus oil as well.
Rather than thinking of essential oils as “yes or no”, “black or white”, think of them in terms of percentages. There will always be a certain percentage of insects who will flee from the odor and a certain percentage that won’t.
For this reason, we recommend using essential oils in combinations with each other or with alternate methods of repelling cockroaches. The aggregate is always more effective than any one of them working alone.
Cedar oil is an interesting case. It turns out to have some chemical properties that are hostile to octopamine, a neurohormone in insects. One of the repellents we’ve reviewed below uses it as an active ingredient and we’ll discuss it when we get there.
Do Ultrasonic Pest Control Devices Work On Cockroaches?
As with the question about the essential oils, it depends on who you ask. Some people swear up and down that ultrasonic repellers worked miracles on their insect problems, while others just as vehemently swear they didn’t do anything.
Since ultrasonic methods rely on the propagation of ultrasonic sound waves, we suspect a lot of it has to do with the placement of the devices, interference from soft furniture (which absorbs sound), and other physical impediments.
Read Also: What’re the best ultrasonic pest repellers?
How do they work in repelling cockroaches?
They emit ultrasonic sounds in the 22-65 Khz frequencies. These sounds are too high pitched for the human ear to detect them – much like a dog whistle.
Insects and other pests can hear them quite easily though. For them, the sounds are extremely irritating and they attempt to avoid them.
The controversy arises because, during the first few weeks of usage, pest activity actually increases because the sounds are stirring them up and driving them out of their homes. After that, according to those who love them, insect activity dropped sharply.
Once again, you need to approach ultrasonic control not as a black or white proposition but as a game of percentages. Play the numbers and you’ll be a happy camper. Demand perfection and nothing will ever satisfy.
What Combinations Work Best?
Rather than relying on one item in the list, we’re fond of combinations. The “one-two punch” phrase made famous in the boxing ring certainly applies to pest control.
Even professionals don’t rely on just one pesticide to eliminate cockroaches, ants, spiders, bed bugs, fleas, or anything else. We always use combinations of pesticides for the best results. You can too with these non-pesticide methods.
We like to recommend a layered approach. Use one method after another, creating multiple barriers for the cockroaches. If one doesn’t get them, the next one will.
In the military, underground bunkers use what is called a cofferdam approach to slow down an incoming blast from an artillery shell a time until blast wave has finally dissipated.
That’s what our layering approach to pest control does. Each layer, ultrasonic, essential oils, chrysanthemum extract, and so on, takes a toll on the cockroach population until finally there is none left.
Two layers should be sufficient but for maximum effectiveness, we recommend three layers. Individually, they’ll all work to a certain degree, but put them together and the cockroaches are going to find themselves in a hurt lock.
What are the Common Mistakes to Avoid When Repelling Roaches?
The number one mistake people make is giving up just before they finally get control of the bugs. We’ve spent years in the pest control field and we’ve never seen a pest problem that was taken care of overnight.
It always takes time.
It’s understandable if you’re impatient when you’re living with them, but don’t give up too soon. Otherwise, you’ll quit just before the last one dies and the problem will start all over again.
Another common mistake is using several different sprays on top of each other. Our layered, or cofferdam approach doesn’t counsel you to do that.
The layers we had in mind are concentric, one after another. Never spray one on top of another as they often tend to cancel each other out. Then you actually wind up with less pest control than you had before, or none at all.
Finally, do all your cleaning and mopping before you spray anything, not after. It seems like a matter of common sense, but we’ve seen too many people come right behind us sweeping and mopping trying to keep their house clean.
While we applaud their initiative, their timing is awful. All their doing is mopping away everything we sprayed. Don’t do that to yourself. Clean and mop first, then spray.
Top 2 Best Cockroach Repellents Reviewed
As a quick recap, here are the cockroach repellents we looked at.
This is a 2-ounce bottle of alcohol-free extract from chrysanthemum flowers, specifically Chrysanthemum x morifolium, from HawaiiParm.
Pyrethrum, the naturally occurring insecticide in chrysanthemums, is in the extract. It can be combined with water, about 10-12 drops per 32-ounce spray bottle, to create an effective repellent.
Spray it in a 6-12 inch wide band around the areas you want protected. Not only can it repel the cockroaches, it can also kill the ones foolish enough to venture across it anyway since that’s exactly what happens in nature.
Because it only takes a few drops of extract for a 32-ounce spray bottle, you’ll be able to make quite a bit of the final solution. You won’t have to worry about odors, stains, poisons, or traps.
It’s very easy to use, and of course, all natural. Unfortunately, in this state, you’ll probably need to reapply it once or twice a week to maintain an effective barrier.
The Good And The Bad
- Simple to use
- No poisons to worry about
- Can yield a large volume of liquid spray
- Needs to be reapplied frequently
Natural indoor Pest Control Spray
This ready-to-use spray from Wondercide is a combination of peppermint and cedar. It comes in a 32-ounce bottle that will cover 400 square feet or the entire perimeter of a 2000 square foot house.
It won’t stain so it is safe to use on furniture and carpets, and it leaves behind a fresh clean scent.
The cedar oil is the active ingredient in this one as it is supposed to block the action of octopamine. In cockroaches, octopamine functions as a neurohormone, controlling the release of trehalose and lipids.
Cockroaches sense the presence of the cedar oil and try to avoid it. The peppermint oil is added primarily as a scent for us, but it also tends to repel cockroaches as well.
There are no poisons or traps to worry about with this spray. It’s easy to use and doesn’t require any mixing when you get it. The downside is that you only get 1 bottle of it when you order it, so it’s a bit more expensive than some other repellents.
The Good And The Bad
- No stains
- Easy to use
- No mixing needed
- Double-acting formula
- Covers 400 square feet
- More expensive than other repellents