Not only are cockroaches difficult to kill, but they don’t seem to be that affected by sound. That being said, if they know predators, such as humans and household pets, are around, they’ll make themselves scarce. As a result, making some level of noise could help keep roaches away.
Cockroaches use a range of sensory organs to detect sound waves and changes in air pressure, including sensory leg hairs, antennae, and an organ called the cerci. This alerts cockroaches of danger, food, and the location of their colony. Because these organs detect vibration, roaches hate the sound of clapping, doors slamming, and stomping. While many ultrasound pest control devices are available, they’ve been proven to be mostly ineffective at keeping the roach population at bay.
Cockroaches’ hearing capabilities aren’t widely documented, but there’s anecdotal evidence that suggests that they prefer to stay away from danger and remain hidden whenever they detect unknown sound waves. That’s one of the reasons why they prefer to come out at night when it’s quieter.
Are Cockroaches Scared of Sound?
Cockroaches can’t hear sound in the same way that humans can. In fact, as described by The Journal of Experimental Biology, American cockroaches are thought to be completely deaf.
However, recordings have found a sense organ that’s extremely sensitive to sound and vibration in nerve five of the metathoracic legs. That being said, this sound only reached 1.8 kHz, which isn’t particularly loud.
Instead, roaches rely on other senses to hear, as described. For example, cockroaches detect danger using their antennae. They also have sensory hairs on their legs that can sense vibration.
Similarly, cockroaches have a pair of sensory organs called the cerci. As Lancaster University describes, these are located on the end of the abdomen and can sense vibrations through the air and on the ground. They work in a similar way to the antennae.
Whenever the cerci feel a vibration, the legs start running, even before the brain receives the signal. This is part of the reason why cockroaches are so hard to catch and kill.
Because cockroaches can’t hear sound very well, loud noises are unlikely to scare cockroaches, unless they cause a significant vibration. While these vibrations might entice roaches to investigate the source in case it means food’s nearby, they’re more likely to encourage the pests to hide until the vibrations subside.
If you’re looking to repel cockroaches using sound, you should aim to accompany the noise with movement so that the pests can detect it.
Sounds That Cockroaches Hate
While cockroaches prefer to come out at night when they’re most protected, they’re relatively brave pests. It’s not uncommon to see cockroaches scurrying across the floor during the day as they look for food and water.
However, if cockroaches know that you’re around, they’ll tuck themselves away in the smallest places until it’s safe to come out. As a result, you may be able to repel them using sounds that cockroaches don’t like.
If you’ve seen a cockroach in your house but don’t know where it’s lurking, stomp around the house to alert the roach that you’re there. While you may feel a bit daft doing this at first, it’s believed that cockroaches can sense the air movements your feet create.
As mentioned, their cerci will kick into action before the cockroach has figured out what’s causing the air movements, causing the pest to scurry out of harm’s way. Amazingly, the time it takes for the legs to detect the movement and start running is around 40 to 50 thousands of a second, meaning you’re unlikely ever to know the cockroach was there.
While you’ll need to deal with the cockroach infestation eventually, stomping is an effective way to keep roaches out of your way while you eliminate the problem.
Clapping has the same effect as stomping. As explained by Scientific American, when you clap your hands, you displace air particles around your hands, creating a compression wave that travels around the air.
Similarly, continuous clapping repeatedly compresses and displaces the air articles, leaving less time between each one. Cockroaches sense the air movement, which tells them that there’s something in their environment that they need to run away from. As a result, clapping causes them to hide.
Many roaches congregate in kitchens and bathrooms where there’s plenty of food and water. Cockroaches eat soap and other starch-based toiletries, so all corners of your house are at risk of an infestation.
However, if you slam kitchen and bathroom cupboard doors, you’re likely to scare cockroaches away – at least while you’re in the room. Again, this won’t remove or eliminate your pest problem, but it makes you less likely to come into contact with a roach, making conditions a bit more bearable.
Do Cockroaches Hate Music?
Cockroaches can’t hear music in the same way we can. This means it won’t attract or repel them. However, cockroaches are likely to be able to detect vibrations from music.
For example, heavy bass music that’s turned up loud will create more vibrations than music played from a quiet radio. However, audio signals cause the radio speaker’s diaphragm to vibrate, making sound waves that roaches can detect.
All the while your music’s playing, cockroaches are likely to avoid the room it’s in, or hide out of the way, at the very least. That’s because the threat level is too great.
Can Roaches Hear Ultrasound?
Ultrasound frequencies greater than 20 kHz are too high for most humans to hear. Similarly, we can’t hear anything below 20 Hz. This is known as infrasonic sound. We’re not as sensitive to ultrasound because our eardrums can’t vibrate as fast as ultrasound waves.
In contrast, the sensory hairs on a cockroach’s legs can detect even the slightest air movement. These hairs also pick up sounds, working alongside the antennae to hear and feel what many other creatures can’t. This allows cockroaches to:
- Evade predators
- Find food
- Detect the weather
What Frequency Repels Roaches?
Ultrasonic pest repellers are becoming a popular cockroach control method by those who don’t want to use toxic fumes around their home.
However, according to the Journal of Economic Entomology, researchers measured nine commercially manufactured pest control devices against German cockroaches. While the devices produced ultrasound, the cockroaches entered the rooms with the devices as readily as rooms without them.
This means that these devices are unlikely to be effective as a pest control method. Similarly, while it’s not yet known which frequencies repel roaches, these findings indicate that while cockroaches can hear ultrasound, they’re not really that bothered by it.
What Sound Waves Keep Roaches Away?
As discussed, electronic high-frequency sound devices are mostly ineffective at controlling roach populations. Not only do roaches ignore the sound, but they get used to it after a little while.
However, longitudinal waves are most likely to be effective against cockroaches. These sound waves are caused by clapping, music woofers, and vibrating drumheads, amongst other things.
Longitudinal waves are when the disturbance moves in the same direction as the wave. Once these waves hit the roach’s sensory organs, the pest will flee. This is why longitudinal waves are the best way to repel cockroaches, keeping them away.
That being said, they won’t keep roaches away for good. They might just be enough to keep them at bay for a short period.
While using sound to repel cockroaches isn’t a widely explored concept, it might work for you. The best thing you can do is try to make as much sound as possible while dealing with a cockroach infestation to drive them into hiding. If you can, leave the radio on in the room you spend the most time in and monitor whether the technique works.