Fly Repellents

Two different kinds of product. Citronella coils, tealights and a reed diffuser are outdoor insect repellents for the area around you - seating, doorways, patios and garden tables. Spray pens and pump sprays are personal repellents applied to skin for bite protection from mosquitoes and other biting insects when you are outdoors.

Outdoors, yes - the citronella products are sold as outdoor insect repellents covering flies and other flying insects around a seating area, and they act on the air immediately around them. Indoors is a different job: a repellent does nothing about flies already in the kitchen, or about whatever is drawing them in. For that, use fly traps or an electric fly killer for the flies inside, and fly screens to stop more arriving.

Outdoors, around the area you are actually sitting in - along the edge of a patio, near a doorway, or around a table. They act on the air immediately around them, so several placed around the perimeter of a seating area do more than one in the middle. Wind moves the scent away, so a sheltered spot makes a noticeable difference.

Coils and tealights involve a naked flame, so site them on a stable, non-flammable surface out of reach of children and pets, and never leave them burning unattended. Personal repellent sprays are for human skin only - read the label for age guidance before using one on a child, and do not apply them to animals. Never use a human insect repellent on a cat.

It varies by product and by conditions. Personal sprays need reapplying through an evening, particularly after swimming or heavy sweating, and the interval is stated on the pack. Coils and tealights burn for a set period per unit, and a diffuser releases over a period of weeks. Check the individual product page for the figures.

For the outdoor products, wind is usually the answer - scent disperses quickly in an exposed position and does far less in a breeze. Move to a sheltered spot and place several around the perimeter rather than one centrally. For a personal spray, check you have covered every exposed area, including ankles and behind the ears, and reapply as often as the label directs. If you are being bitten in daylight near water or long grass, the insect may be a midge or a horsefly rather than a mosquito, which changes what helps.

Repellents reduce insects bothering you where you are, for as long as they are working. They do not reduce the number present in the area. If the aim is fewer insects over time rather than one untroubled evening, a trap is the better tool - and the two work perfectly well together.