When the team sat round the table this morning to discuss features for the day, three colleagues spoke up about the sudden surge in flies. Sarah Maber, GH’s news and features director said:
‘I am VERY sensitive about the buzzing ones and cannot focus on anything until they’re GONE from whatever room I’m in, so spend far too long trying to wave them out of doors. We have taken to trapping them behind curtains but then I just feel sad that they will die. We now hermetically seal ourselves in – even in the hot weather, so no more flies appear!’
Flies are always a problem in the heat of summer. The eggs hatch more readily, and our bins rot more quickly, so a fly or two is bound to find its way indoors. But, when there’s several constantly hovering near our food, setting up a nest in our bin, or just outright hitting us in the face, that’s when we need to take action. I spoke to Adam Hart, professor of conservation ecology at the University of Gloucestershire and a Fellow of the Royal Entomological Society, to find out why flies are such a nuisance right now and the best way to get rid of them.
Why is my home suddenly filled with flies?
According to Adam: ‘At this time of year, the larger flies people notice indoors are often blowflies or flesh flies, alongside the familiar housefly. People often think they’ve suddenly been invaded, but what they’re really seeing is the effect of warm weather. Heat speeds up their development and makes adults much more active.
‘It’s also worth remembering that flies are excellent at finding food. They’re especially interested in kitchen waste, pet food, compost and anything organic that’s starting to decay. Our homes can be surprisingly attractive to them.’
So, with the sun hitting our bins and food waste decaying more readily, flies are bound to make an entrance. And they will easily find their way in, day or night, through the many open windows and doors. While they predominantly rest at night, flies are still attracted to the light – so that’s another consideration if you’re noticing a spike at home.
Adam continues: ‘If dozens of large flies suddenly appear over a day or two, it’s worth considering whether there’s a dead bird or rodent in a loft or wall cavity, or whether you have a bag of rubbish somewhere it shouldn’t be. It can be worth double bagging bags that contain food or organic waste when it’s very hot, and making sure bin lids fit really tightly.
‘The best way to keep numbers down is to make your home less inviting. Keep food covered, empty bins regularly, clear away pet food, and don’t leave compost or food waste close to open doors and windows. Fly screens are very effective if you have them.’
While it’s always better to find a long-term solution for keeping flies out, if you urgently need a makeshift fly trap to deal with a surge in numbers, here’s what we recommend.
The DIY fly trap that takes minutes to assemble
1. Take a large, empty plastic 2-litre bottle (a milk jug can also work).
2. Rinse it out to remove any remnants.
3. Cut it in half with a pair of scissors.
4. The type of fly you’re dealing with varies the bait you’ll want to use in the bottom segment:
Adam continues: ‘For fruit flies, apple cider vinegar with a few drops of washing-up liquid is probably the classic DIY trap. The vinegar mimics fermenting fruit, while the detergent breaks the surface tension so the flies can’t escape.
‘House flies are much less specialised than fruit flies and are attracted to a wide range of food odours. Something that’s fermenting or decomposing tends to be more attractive than plain sugar. Yeast mixed with a little sugar and warm water can work well because it produces fermentation odours that many flies find appealing.’
With the above in mind, for house flies, we recommend combining 1tbsp of sugar with 1tsp of yeast and 200ml of warm water.
5. Invert the top of the bottle and place into the base section to create a funnel, making sure the lid doesn’t contact the solution and tape it in place.
6. Then leave it out to get to work.
This trap takes minutes to assemble and will last for about a week, but replace it as and when it fills with flies.
Adam stresses that ‘None of these DIY traps are especially selective or guaranteed to be highly effective. The most effective long-term solution is still the boring option! Remove the food source or breeding site that’s attracting them in the first place.’
DIY fly trap kit
