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How to use an ultrasonic pest repeller

Updated: October 2026

The plug is in the hallway, the kitchen door is shut, and you are waiting for the rest of the flat to change. Learning how to use an ultrasonic pest repeller starts smaller than the title: one open socket in the room you care about, on a mode you can live with, for the seller’s timetable and no longer if the signs continue. Prices sit on the [ultrasonic pest repeller comparison](/hub/pest-control/ultrasonic-pest-repeller). This page is placement. Peter F. used the amazon.co.uk listings and public UK notes on 16 October 2026. We did not run a placement trial. A qualifying purchase can earn us a commission at no extra cost to you.

The plug is in the hallway, the kitchen door is shut, and you are waiting for the rest of the flat to change.

Our top picks

Siyuio Siyuio 6-pack, 4 modes

Best overall

Siyuio Siyuio 6-pack, 4 modes
7.9/10about £23.74
View offer
VNEED VNEED plug-in repeller

Preis-Tipp

VNEED VNEED plug-in repeller
7.3/10about £16.14
View offer
FunBean FunBean 4-pack plug-in

Alternative

FunBean FunBean 4-pack plug-in
7.0/10about £24.99
View offer
On this page
  1. 1.One room, one socket
  2. 2.Where in the room
  3. 3.Which mode to leave on
  4. 4.How long to leave it
  5. 5.Stop if the loft may hold bats, or if the plug is unsafe

One room, one socket

Ultrasound reflects, and it does not bend around corners. FunBean, Siyuio, TruSky, T-MENG, both BLIAZAY listings, and the XY-002 say that the waves do not pass through walls. A hallway unit does not serve a closed bedroom. Three shut doors means three sockets, not the square feet in the title. Pestbye’s whole-house line does not cancel that. Count the enclosed rooms, then see if the pack matches. Pack size is on the buying guide.

Where in the room

Put the plug where the face of the unit can see the room. A curtain or the back of a sofa is the usual way to hide it by accident. Height is not one number. TruSky says about 10–50 inches above the floor, roughly 25–127 cm, and still says one unit per enclosed room. The XY-002 listing prints about 0.65–1.65 ft, roughly 20–50 cm, with clear surroundings. The other brands do not share a height. Use a socket you can see, and do not put the unit in a cupboard. It has to suit a BS 1363 socket. If it will not seat, sparks, or runs hot, unplug it.
Siyuio Siyuio 6-pack, 4 modes

Testsieger

Siyuio Siyuio 6-pack, 4 modes
7.9/10about £23.74
View offer

Which mode to leave on

A unit you switch off at night is not covering that room. Siyuio calls blue suitable for bedrooms or when pets are around, and red the maximum for an empty house. FunBean’s red mode is 10–15 kHz, and the same bullet says not to use it with people or pets indoors. If everyone is home, leave red off. REPELIX calls mode 1 the quietest and still says sensitive hearing may notice it. VNEED’s seller text says the output is inaudible, and reviews describe a click and a pulsing blue light, with no mode to turn the click down. Dogs, children, and pet rodents are not one group. Use the pets page. A blue glow that faces the bed is a reason to turn the plug or move the socket.

How long to leave it

Seller timetables do not agree, and they are not a trial. FunBean says one to two weeks for an initial change and three to four weeks for something more noticeable. T-MENG says about three or four weeks. Treat those as printed schedules. If droppings or scratching continue after the seller’s own window, the plug has not become the plan. The mice page is that decision, including why a cavity can stay busy while the socket is on. Leave the unit in the open room you chose.

Stop if the loft may hold bats, or if the plug is unsafe

Do not plug a unit into a loft that might be a bat roost. The British Pest Control Association and the Bat Conservation Trust both say not to use ultrasonic deterrents in or near a roost. Intentional or reckless disturbance can be an offence. Pestbye’s bullets mention a loft and do not mention bats. That silence is not permission. Unplug the unit if it runs hot, sparks, smells, or will not sit in the socket. A failed product is a question under the Consumer Rights Act 2015. An infestation that continues, especially in a food business or where the problem is spreading, is the point where a professional should take over. A plug at 3–6 W does not close the holes the animals are using.

Common questions

Does it work through a closed door or a wall?
No. Sellers in this set say the waves do not pass through walls, and an STV sheet for a different product says the same about doors, furniture, and cavities. One hallway plug does not treat the rooms behind closed doors. Use one unit in each enclosed room, with the face of the unit in the open.
How high should the socket be?
Only two listings print a height, and they do not match. TruSky says about 10–50 inches above the floor. The XY-002 listing says about 0.65–1.65 ft, with clear surroundings. The other brands are silent. Use an unobstructed socket you can see, and do not treat either range as a rule for every plug.
How long do sellers say to leave it on?
FunBean prints one to two weeks, then three to four. T-MENG prints about three or four weeks. Another brand’s sheet, not in this set, prints one to three weeks. Those are seller timetables. They are not a promise that the room will be clear when the window ends.
Can you put it behind the sofa?
You can plug it in there, and you will have hidden it. Ultrasound does not travel usefully through soft furnishings, curtains, or cupboard doors. Leave the face of the unit open to the room. If the only free socket is behind a large sofa, that room is a poor place for this kind of device.
When do you stop and get a person in?
Stop if scratching and droppings continue after the seller’s timetable, if you cannot tell bats from rodents, if the building handles food, or if the problem is spreading. Also stop if the plug runs hot, sparks, or will not seat. A professional handles the infestation. A hot plug is a reason to unplug it.

Related pages

Best ultrasonic pest repeller

Ultrasonic pest repeller

Ultrasonic pest repeller buying guide for a UK plug

Ultrasonic pest repeller for mice: holes and sound

Ultrasonic pest repeller safe for pets, dogs and cages

Sources

Public UK sources and the amazon.co.uk listings in this set, last checked on 16 October 2026.

  1. ASA, pest repellents (retrieved 16 October 2026)
  2. GOV.UK, code of practice on rodent infestations on poultry farms (retrieved 16 October 2026)
  3. BPCA, pest control while protecting bats (retrieved 16 October 2026)
  4. BPCA, mouse control (retrieved 16 October 2026)
  5. BPCA, the hearing of rats (retrieved 16 October 2026)
  6. Bat Conservation Trust, bats in a property (retrieved 16 October 2026)
  7. Electrical Equipment (Safety) Regulations 2016, regulation 35 (retrieved 16 October 2026)
  8. GOV.UK, bats: protection and licences (retrieved 16 October 2026)