Pests have plagued gardeners since the Agricultural Revolution. Hordes of: locusts, mice and other rodents, deer – the list of creatures happy to take advantage of human efforts in the garden is seemingly limitless. There may be hope, though. An ultrasonic repeller may be able to help protect your garden from the ravages of many different pests.

Ultrasonic repellers work on a very simple basis – they emit very high frequency sounds. These sounds are out of the human range of hearing, but they can be heard by many pests, including most insects and rodents. The sounds emitted by the repeller are painful enough to drive these creatures away from the treated area, but are not enough to kill them, offering a humane, yet effective way of dealing with some pests.

Newer repeller models offer a number of unique features. For instance, some can be set to the specific type of pest you are trying to prevent, including rodents, bats, deer, insects and even household cats and dogs. They can also be used indoors and outdoors (note that you must purchase an indoor/outdoor model to use it outdoors).

When looking for an ultrasonic model, compare the effective range. Some models are only effective for a relatively small radius, while others have a larger range. Use this to determine the number of repellers needed for your garden size, or your home. Depending on the pests you’re targeting, it may also make sense to find a model with automatic motion detection. If motion detection is important to you, make sure the unit offers a decent range (15 feet is a good average).