Cat repeller

Household cat

Wild cat (ultrasonic devices unlikely to work)

A cat repeller is a device or substance used to discourage cats from entering an area, or to encourage them to leave if they do enter. Such deterrents are most commonly used by gardeners, in order to prevent damage to their gardens, to avoid cat feces, or to protect birds.

Devices

Ultrasonic devices

A cat lies on a treestump in a garden

Many retailers sell devices which exploit the discomforting effects of in-air ultrasound. These devices are usually combined with a motion sensor which is triggered by movement within the sensors range. This causes the device to emit high frequency noise which is uncomfortable to the cats, and inaudible to most humans (although they can still experience unpleasant subjective effects and, potentially, shifts in the hearing threshold^[1]). The devices are available in both battery and mains operated forms, the latter generally having a higher output, greater range and requiring less attention.

Some cats are immune to ultrasonic cat deterrents, mainly the ones which are hard of hearing. There are also reports that the devices take a while to become effective, as some cats will stand their ground in a futile attempt to make the deterrent go away. Moving the device to different locations regularly and combining with another form of cat repellent may make these devices more effective.

The Royal Society for the Protection of Birds (RSPB), has endorsed a commercial product called "CatWATCH"^[2], for which it receives 2% of the wholesale price of every device sold by the manufacturer^[3]. The RSPB tested the original CatWATCH device in a study using 63 and 96 volunteer observers in two long-running (18 and 33 weeks) blind experiments^[4] . Results from the study indicated that the device did have a moderate deterrent effect, reducing the probability of a previous cat intrusion into a garden by approximately 32% in the first experiment, but not in the longer running second experiment^[5].

Scatter guns are another form of ultrasonic device. These laser-aiming devices can be targeted at cats and activated by a trigger. They will send out an ultrasonic noise directed where aimed.

Professor Tim Leighton from the Institute of Sound and Vibration Research has expressed concern about the recent growth in commercial products which exploit the discomforting effects of in-air ultrasound^[1]. 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^[1].

Electric fences

A variety of commercially produced electric fences are also available, with voltages low enough to deter but not cause harm to cats. Care must be taken with the strength of electric current used; one Cumbria pensioner received a fine for setting up a system based on a 12v battery charger, knowingly allowing a dangerously high current to flow through the wiring as he had lied about using a battery charger and had instead had used the 230v mains electricity supply to energize the wiring. ^[6][7].

Cats Protection describe the use of electric fences as "barbaric" on their website due to the physical harming of a cat or any other creature that comes into contact with an electric fence.

Substances

Crystals

A more traditional cat repeller is to use jelly-like crystals containing methyl nonyl ketone, designed to be scattered around the garden, or around the areas the cat likes to foul. These repellents give off a smell that is very unpleasant to the cat, causing it to avoid that place.

Citronella

Citronella oil, famous for repelling flying insects and other creepy crawlies, can also be used to get rid of cats. Citronella sticks are a common form, coming in citronella-impregnated plastic "repeller sticks".

Lion dung

Lion dung has been reported to be an effective method of deterring cats, and has received support from the British organisation Cats Protection. One anecdotal experience reported by the BBC^[8] found that it was not terribly effective however.

References

1. ^ ^{a b c} Leighton, Tim (2007). "What is Ultrasound?". Progress in Biophysics and Molecular Biology 93 (1-3). doi:10.1016/j.pbiomolbio.2006.07.026. http://www.sciencedirect.com/science/article/pii/S0079610706000812. Retrieved 19 November 2011. 
2. ^ "RSPB endorses ultrasonic cat deterrent". Royal Society for the Protection of Birds. http://www.rspb.org.uk/advice/gardening/unwantedvisitors/cats/catdeterrent.asp. 
3. ^ "Concept Research". http://www.conceptresearch.co.uk/cats_1.htm. Retrieved 19 November 2011. 
4. ^ Nelson et al. (2006). "The efficacy of an ultrasonic cat deterrent". Applied Animal Behaviour Science 96 (1-2): pp 83-91. doi:doi:10.1016/j.applanim.2005.05.005. http://www.sciencedirect.com/science/article/pii/S0168159105001383. Retrieved 19 November 2011. 
5. ^ Nelson et al. (2006). "The efficacy of an ultrasonic cat deterrent". Applied Animal Behaviour Science 96 (1-2): pp 83-91. doi:doi:10.1016/j.applanim.2005.05.005. http://www.sciencedirect.com/science/article/pii/S0168159105001383. Retrieved 19 November 2011. 
6. ^ "Pet killed by 'electric fence'". BBC News. 2003-05-22. http://news.bbc.co.uk/1/hi/england/cumbria/3049297.stm. Retrieved 2010-04-28. 
7. ^ Pet cat fried on electric fence | Metro.co.uk
8. ^ BBC News | ENGLAND | Cat-astrophic feline deterrent at news.bbc.co.uk

External links