Electronic pest control
Encyclopedia
Electronic pest control is the name given to the use of any of the several types of electrically powered devices designed to repel or eliminate pests, usually rodents or insects.
Numerous electronic pest control devices are readily available throughout the world. Hardware stores and garden centers usually stock some sort of electronic device advertised to repel a variety of pests and one can also find them on the internet. Although these devices have been around for at least 20 years, they have only recently become popular and widely advertised, probably due to their environmentally friendly claims.
There is a wide range of opinion about these devices. Some people claim that they work for them, while others claim they are not effective at all.
Since these devices are not regulated under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) in the United States, the US EPA does not require the same kind of efficacy testing that it does for chemical pesticides.
Ultrasonic devices operate by emitting short wavelength, high frequency sound waves too high in pitch to be heard by the human ear (all frequencies greater than 20,000 Hz). This is due to limitations in human hearing
. Humans can not hear ultrasound because the eardrum
does not vibrate fast enough, but some animals such as dogs, bats and rodents can hear well into the ultrasonic
range. Some insects, such as grasshopper
s and locusts can detect frequencies from 50,000 Hz to 100,000 Hz, and moths
and lacewings can detect ultrasound
as high as 240,000 Hz produced by insect-hunting bats.
Insects detect sound by special hairs or sensilla
located on the antennae (mosquitoes) or genitalia (cockroaches), or by more complicated tympanal organs (grasshoppers, locusts, moths and butterflies).
Electromagnetic pest repelling devices claim to alter the electromagnetic (EM) field of household wiring, and vibrate the electromagnetic field that always exists around the wiring in the walls of your house.
study confirmed that ultrasonic
sound devices do have both a repellent effect as well as a reduction in mating and reproduction of various insects. However, the results were mixed and ultrasonic sound had little or no effect on some pests. Ultrasonic devices were highly effective on cricket
s while the same devices had little repellent effect on cockroaches
. Additionally the results were mixed with some devices being effective while others having no effect depending on the test subject. The study also concluded there was no effect on ant
s or spiders in any of the tests. They concluded, based on the mixed results, that more research is needed to improve these devices.
A 2002 study by Genesis Laboratories Inc. does lend some credence to the ability of electronic repellent devices to repel certain pests in controlled environments. “Preliminary study of white-footed mice behavior in the test apparatus demonstrated a significant preference for the non-activated chamber among both sexes.” This study was sponsored by Global Instruments, the maker of the "Pest-a-cator" series of electronic repellent devices.
In 2003, the Federal Trade Commission required Global Instruments, the maker of the Pest-A-Cator/Riddex series of electromagnetic pest control devices, to discontinue any claims for their efficacy until they are backed by credible scientific evidence. This ban continues to be in effect.
Victor Pest managed to obtain positive results from independent researchers which resulted in two ultrasonic devices being granted registration by the Canadian EPA(PMRA). The results from the tests were the device “successfully repelled the rodents from the protected area in 13 of the 17 sites. This represents a 81.3% success rate...the average number of days before rodent activity was stopped was six days.”
Cockroaches initially respond to electronic pest control devices by moving about a bit more than usual, but don't appear overly eager to escape from the sound waves. This includes devices that emit uniform frequency as well as changing frequencies of ultrasound. Rodents adjust to the ultrasound (or any new sound) and eventually ignore it. However, researchers were able to use the increased cockroach activity to good effect by increasing the rate they caught the roaches in sticky traps. At best, ultrasonic waves have only a partial or temporary effect on rodents. Numerous studies have rejected ultrasonic sound as a practical means of rodent control.”
Tests of commercial ultrasonic devices have indicated that rodents may be repelled from the immediate area of the ultrasound device for a few minutes to a few days, but they will nearly always return and resume normal activities. Other tests have shown that the degree of repellence depends on the frequency, intensity, and the pre-existing condition of the rodent infestation. The intensity of such sounds must be so great that damage to humans or domestic animals would also be likely. Commercial ultrasonic pest control devices do not produce sounds of such intensity.
The UK's independent Advisory Group on Non-ionising Radiation (AGNIR) produced a 180 page report on the health effects of human exposure to ultrasound and infrasound in 2010. The UK Health Protection Agency (HPA) published their report, which recommended an exposure limit for the general public to airborne ultrasound sound pressure levels (SPL) of 70 dB (at 20 kHz), and 100 dB (at 25 kHz and above).
is featured in a season 5 episode of The Big Bang Theory
, sending Sheldon
into an ornithophobic
episode and causing him to build an ultrasonic noise generator in an attempt to drive the bird from his windowsill. He only succeeds in shattering his window.
Numerous electronic pest control devices are readily available throughout the world. Hardware stores and garden centers usually stock some sort of electronic device advertised to repel a variety of pests and one can also find them on the internet. Although these devices have been around for at least 20 years, they have only recently become popular and widely advertised, probably due to their environmentally friendly claims.
There is a wide range of opinion about these devices. Some people claim that they work for them, while others claim they are not effective at all.
Since these devices are not regulated under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) in the United States, the US EPA does not require the same kind of efficacy testing that it does for chemical pesticides.
Types of Devices
There are basically two types of electronic pest control devices widely available, these are Ultrasonic and Electromagnetic.Ultrasonic devices operate by emitting short wavelength, high frequency sound waves too high in pitch to be heard by the human ear (all frequencies greater than 20,000 Hz). This is due to limitations in human hearing
Hearing (sense)
Hearing is the ability to perceive sound by detecting vibrations through an organ such as the ear. It is one of the traditional five senses...
. Humans can not hear ultrasound because the eardrum
Eardrum
The eardrum, or tympanic membrane, is a thin membrane that separates the external ear from the middle ear in humans and other tetrapods. Its function is to transmit sound from the air to the ossicles inside the middle ear. The malleus bone bridges the gap between the eardrum and the other ossicles...
does not vibrate fast enough, but some animals such as dogs, bats and rodents can hear well into the ultrasonic
Ultrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...
range. Some insects, such as grasshopper
Grasshopper
The grasshopper is an insect of the suborder Caelifera in the order Orthoptera. To distinguish it from bush crickets or katydids, it is sometimes referred to as the short-horned grasshopper...
s and locusts can detect frequencies from 50,000 Hz to 100,000 Hz, and moths
Moths
Moths may refer to:* Gustav Moths , German rower* The Moths!, an English indie rock band* MOTHS, members of the Memorable Order of Tin Hats...
and lacewings can detect ultrasound
Ultrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...
as high as 240,000 Hz produced by insect-hunting bats.
Insects detect sound by special hairs or sensilla
Sensilla
A sensillum is an insect sensory organ protruding from the cuticle, or sometime lying within or beneath it. Sensilla are divided in chemical, mechanical , thermal and visual....
located on the antennae (mosquitoes) or genitalia (cockroaches), or by more complicated tympanal organs (grasshoppers, locusts, moths and butterflies).
Electromagnetic pest repelling devices claim to alter the electromagnetic (EM) field of household wiring, and vibrate the electromagnetic field that always exists around the wiring in the walls of your house.
Effects on Pests
"Ultrasound and Arthropod Pest Control" an extensive Kansas State UniversityKansas State University
Kansas State University, commonly shortened to K-State, is an institution of higher learning located in Manhattan, Kansas, in the United States...
study confirmed that ultrasonic
Ultrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...
sound devices do have both a repellent effect as well as a reduction in mating and reproduction of various insects. However, the results were mixed and ultrasonic sound had little or no effect on some pests. Ultrasonic devices were highly effective on cricket
Cricket (insect)
Crickets, family Gryllidae , are insects somewhat related to grasshoppers, and more closely related to katydids or bush crickets . They have somewhat flattened bodies and long antennae. There are about 900 species of crickets...
s while the same devices had little repellent effect on cockroaches
Cockroaches
A cockroach is an insect of the order Blattaria. "Cockroach" may also refer to:*Cockroach , a 2001 album by Danger Danger*Cockroach , a 2008 novel by Rawi Hage...
. Additionally the results were mixed with some devices being effective while others having no effect depending on the test subject. The study also concluded there was no effect on ant
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
s or spiders in any of the tests. They concluded, based on the mixed results, that more research is needed to improve these devices.
A 2002 study by Genesis Laboratories Inc. does lend some credence to the ability of electronic repellent devices to repel certain pests in controlled environments. “Preliminary study of white-footed mice behavior in the test apparatus demonstrated a significant preference for the non-activated chamber among both sexes.” This study was sponsored by Global Instruments, the maker of the "Pest-a-cator" series of electronic repellent devices.
In 2003, the Federal Trade Commission required Global Instruments, the maker of the Pest-A-Cator/Riddex series of electromagnetic pest control devices, to discontinue any claims for their efficacy until they are backed by credible scientific evidence. This ban continues to be in effect.
Victor Pest managed to obtain positive results from independent researchers which resulted in two ultrasonic devices being granted registration by the Canadian EPA(PMRA). The results from the tests were the device “successfully repelled the rodents from the protected area in 13 of the 17 sites. This represents a 81.3% success rate...the average number of days before rodent activity was stopped was six days.”
Cockroaches initially respond to electronic pest control devices by moving about a bit more than usual, but don't appear overly eager to escape from the sound waves. This includes devices that emit uniform frequency as well as changing frequencies of ultrasound. Rodents adjust to the ultrasound (or any new sound) and eventually ignore it. However, researchers were able to use the increased cockroach activity to good effect by increasing the rate they caught the roaches in sticky traps. At best, ultrasonic waves have only a partial or temporary effect on rodents. Numerous studies have rejected ultrasonic sound as a practical means of rodent control.”
Tests of commercial ultrasonic devices have indicated that rodents may be repelled from the immediate area of the ultrasound device for a few minutes to a few days, but they will nearly always return and resume normal activities. Other tests have shown that the degree of repellence depends on the frequency, intensity, and the pre-existing condition of the rodent infestation. The intensity of such sounds must be so great that damage to humans or domestic animals would also be likely. Commercial ultrasonic pest control devices do not produce sounds of such intensity.
Safety
Professor Tim Leighton from the Institute of Sound and Vibration Research, Universtity of Southampton, United Kingdom produced a 83 page paper entitled "What is Ultrasound" which was published in 2007. In the paper Leighton expressed concern about the growth in commercial products which exploit the discomforting effects of in-air ultrasound (to pests for whom it is within their audible frequency range, or to humans for whom it is not, but who can experience unpleasant subjective effects and, potentially, shifts in the hearing threshold). Leighton claims that commercial products are often advertised with cited levels which cannot be critically accepted due to lack of accepted measurement standards for ultrasound in air, and little understanding of the mechanism by which they may represent a hazard.The UK's independent Advisory Group on Non-ionising Radiation (AGNIR) produced a 180 page report on the health effects of human exposure to ultrasound and infrasound in 2010. The UK Health Protection Agency (HPA) published their report, which recommended an exposure limit for the general public to airborne ultrasound sound pressure levels (SPL) of 70 dB (at 20 kHz), and 100 dB (at 25 kHz and above).
In Popular Culture
A Black-throated Magpie-JayBlack-throated Magpie-jay
The Black-throated Magpie-Jay is a strikingly long-tailed jay of northwestern Mexico.-Description:This species is 58.5 to 76.5 cm long, more than half of which is the tail, and weight is 225-251 grams...
is featured in a season 5 episode of The Big Bang Theory
The Big Bang Theory
The Big Bang Theory is an American sitcom created by Chuck Lorre and Bill Prady, both of whom serve as executive producers on the show, along with Steven Molaro. All three also serve as head writers...
, sending Sheldon
Sheldon Cooper
Sheldon Lee Cooper, B.S., M.S., M.A., Ph.D., Sc.D. is a fictional character from Texas on the CBS television series The Big Bang Theory, portrayed by actor Jim Parsons...
into an ornithophobic
Ornithophobia
-Symptoms:Ornithophobia can cause the following symptoms: breathlessness, dizziness, excessive sweating, nausea, dry mouth, feeling sick, shaking, heart palpitations, inability to speak or think clearly, a fear of dying, becoming mad or losing control, or a full-blown anxiety attack.-In popular...
episode and causing him to build an ultrasonic noise generator in an attempt to drive the bird from his windowsill. He only succeeds in shattering his window.