Every action you take has to be considered in terms of how many flies it’ll let into your home.’ One fed-up homeowner, Colin Readwin, told the BBC last month: ‘We’ve had candles going, we’ve had fly spray, we’ve been flicking them with dusters and they’re buzzing around your head. When candles and fly spray don’t fix the problem, what can you do? Wasps, which are one of the most effective predators of flies, have also been affected by this year’s unusual weather. The fumes will keep flies away for around three hours, even if you leave your doors and windows open.