Electronic & Ultrasonic Ant Repellers

These are dual-action units. The ultrasonic setting emits sound above the range of human hearing into the room; the electromagnetic setting sends pulses through the house wiring instead, with an LED showing which is running. Pest-Stop lists ants among the pests its indoor repellers target, and describes the waves as causing auditory distress to crawling insects, discouraging their presence in the home. There is no poison and nothing to clear up.

Use both. Bait is what reaches the nest - foragers carry it back and it acts on the colony, which is what stops a trail returning. Put down ant bait stations first, then run a repeller alongside them to discourage the next lot from settling. Read our guide on getting rid of ants yourself for the full sequence.

Ultrasonic output goes into the room the unit is plugged into. The electromagnetic setting sends pulses through the building's electrical wiring instead, so a single unit can cover multiple rooms on the same circuit. Units are sold by the area they cover - one room, small house or large house - so check the coverage stated on the product page and choose to suit the space.

No. Ultrasonic sound does not pass through walls, closed doors or furniture, and carpets, curtains and upholstery absorb it. Plug the unit into an open part of the room with nothing in front of it, or switch to the electromagnetic setting where you need to reach beyond one room.

There is no active substance and no poison - the unit plugs in and runs on mains power, so there is nothing to touch or swallow, and Pest-Stop states its indoor repellers are harmless to pets, children and pregnant women. The exception is pet rodents and rabbits: hamsters, gerbils, guinea pigs, rabbits and chinchillas hear well into the ultrasonic range and may be distressed, so do not run one in a room where they are kept. Use as directed.

Two different situations look the same here. If a single trail is still running to a food source indoors, nothing has yet reached the nest - put bait down on the trail, leave it undisturbed, and do not spray the trail while bait is out, because killing the foragers stops the bait getting back to the colony. If ants keep turning up in new places instead, they are coming in from outside and the answer is sealing the route around door thresholds, pipework and window frames. Our guide has ten ways to stop ants coming into the house.

In the room with the problem, at socket height, with nothing solid in front of it - not behind a sofa, inside a cupboard or under a shelf. Leave it running continuously rather than switching it on and off, and keep it clear of soft furnishings that would absorb the sound.