The coil, the plug-in, the net: what the nighttime mosquito kit really does, and its honest bill

Nobody is anti-mosquito-product - the industry is simply clearer when you read it as layers rather than purchases: one product never does what the poster says, and the products differ wildly in what they cost your lungs versus what they cost the mosquitoes. This is the layer diagram for a bedroom in this city.

What each product actually does

• Coils and vaporiser liquids are repellent/knockdown insecticides - usually pyrethroids: they confuse and down the mosquitoes near the treated air, which is why the bites stop while it burns. They do not clear the room; they interrupt the raid, and they work on the female you can hear, not the population. Which means: ventilation is part of the dosage - a lit coil or a plug-in running all night in a sealed room is an inhalation decision for everyone with a pulse, children included. The sane pattern: burn/plug in the room in the early evening with the window open, mosquitoes down, then sleep in aired air - not sleep inside the smoke.
• Grid UV "mosquito machines" are largely a theatre purchase - hosts find biting mosquitoes by carbon dioxide and body heat, not by flying into a lamp across the room, and the grid mostly executes moths and beetles - the harmless half of the night's traffic. They can shave a few from an outdoor seating area; as your malaria layer they are a rounding error.
• Sprays on walls and nets are the quietly professional one: the net's mesh is the barrier that stops every bite in its radius; a long-lasting insecticide treatment on the net (the kind the clinics distribute for a reason) adds knockdown to mesh that a bitten-through edge can undo. Inspect edges before trusting them.

The base layer no product replaces

Every device is downstream of the maths: female mosquitoes around a house breed in finger-caps of standing water - gutter troughs, the drum lid, tyre swings, the plant trays, the air-conditioner drip that never dries. A weekly walk emptying and scraping, plus the fan trick that people under-rate - a ceiling or standing fan on the bed genuinely reduces landing, because weak fliers cannot steer in moving air - removes more biting pressure than any single purchase. And the personal layer that costs nothing: light-coloured long sleep-wear for the pre-midnight hours, when the evening species hunt hardest.

The honest stack for a bedroom

Fan or net as the sleep layer; early-evening coil or plug-in with the window open, switched off before you sleep - or a bedroom-rated liquid vaporiser used per its label in a ventilated room; screen the window the mosquitoes fly in through at dusk if the net is not your style; one weekly water walk; and for the outdoor sit, the coil goes on the upwind edge of the seating, never between people and the breeze. It is less glamorous than the gadget poster. It bites - stops biting - less than the poster.