If an ultrasonic machine does not eliminate the wasps, or if you prefer a non-electronic method, try using one of the other types of wasp repellent products, such as the Waspinator, a nest-shaped bag that testers at Clean Air Gardening says will repel wasps and yellow jackets without the use of harmful chemicals or electricity. Hang the fake nest outside on the patio or in the garden to trick the wasps into thinking the area is already inhabited by an enemy nest.
People with acute high frequency hearing may be bothered by some of the sounds emitted by ultrasonic pest repellents. Pest repellents are not harmful for most humans, cats, dogs, birds and reptiles, but they are very unpleasant and disturbing for some small pets, and according to Safe Home Products, "Pet mice, gerbils, hamsters, guinea pigs, hedgehogs, ferrets and tarantulas should be kept away from the unit."
Electronic insect repellents are small ultrasonic devices that emit high frequency sound waves, the purpose of which is to repel or scare away insects. Some insect species--such as wasps, spiders, beetles and bees--sense ultrasonic vibrations, produce or perceive sound in ultrasonic frequencies and are affected by high-frequency sounds. The use of sound to repel wasps has not been scientifically proven, though products exist that claim to do just that. According to the Biocontrol Network, "it would take years and millions of dollars to test the effects of any electronic pest control device" on even one household pest group such as wasps.
Insert batteries or, if operated by electricity, plug the repellent's adapter into an electrical outlet.
Protect the pest-repelling device from moisture and extreme temperatures, especially if using it outdoors where wasps tend to gather. Look for devices that are manufactured for outdoor use, that are heavy duty and that have all-weather construction, so they can be safely used both indoors and outdoors.
Place the device, either free-standing or suspended, in the optimal location to repel the wasps.
Follow the specific machine's instructions for setting and adjusting the sound volume and sound frequency to the appropriate levels for repelling wasps.
Turn on the device.
Maura Wolf's published online articles focus on women, children, parenting, non-traditional families, companion animals and mental health. A licensed psychotherapist since 2000, Wolf counsels individuals struggling with depression, anxiety, body image, parenting, aging and LGBTQ issues. Wolf has two Master of Arts degrees: in English, from San Francisco State University and in clinical psychology, from New College.