Cluster Flies

Cluster Flies – Strength in Numbers

Houseflies are annoying to get rid of, but cluster flies are a few thousand times worse than that! As their name suggests, these tiny flies live in massive swarms. They make their homes in loft spaces up and down the country, spreading germs and dirt while also attracting other pests and leaving their trademark stale odour wherever they go.

Cluster flies are tricky to deal with for one reason only; their numbers. Normal electric fly killers and other regular pest control products will be quickly overwhelmed by massive swarms of flies, and if you don’t get them all the swarm will be back with a vengeance next year. So how can you get rid of cluster flies for good? Our buyer’s guide will tell you all you need to know so you can get the right tools for the job.

Understanding Cluster Flies

To get rid of cluster flies, you need to understand a bit about what makes them tick. This is because they’re not like regular flies and getting rid of them isn’t so easy! As we mentioned above, the swarms will return to the same spot year after year if you don’t get rid of them properly, so you can never be too prepared when it comes to these persistent pests.

Life Cycle

Through the summer, cluster flies live outdoors and don’t really bother anyone. In many ways, they’re actually more hygienic than regular flies as they don’t search for food waste and animal droppings to lay eggs. Instead, they breed by laying eggs on earthworm casts. When the eggs hatch, the tiny larvae crawl inside the worms and eat them from the inside! This morbid method of breeding means you’re far more likely to find cluster flies in rural areas or around the coast.

Where You’ll Find Them

Once grown, the adult flies join the swarm and they continue to live outside until the end of summer. When the weather turns cool, they’ll look for somewhere warm and dry to shelter through the winter, which often leads them into our homes! They usually slip into attics as these loft spaces are normally quieter and warmer, although they can sometimes crawl through voids in the wall into any other part of the home as well. What this all means is that many people don’t even realise they have a cluster fly problem they go into the attic to get their Christmas decorations down!

Seeing (and Smelling) the Warning Signs

Even if you already know you have cluster flies, you should still learn about how to spot an infestation in case the same swarm comes back next year. When they leave your loft, cluster flies leave a pheromone trail which will lead the swarm right back there next year while also attracting other pests, so it’s vital that you take out the whole swarm as early as you can, while they’re still in your loft.

The first sign you might notice is a stale, sickly sweet odour coming from your attic space. This comes from fly saliva, which they like to leave all over your walls (which is how they spread the pheromone marker). Be sure to investigate your loft space if you smell anything unusual up there. If you live in a rural area, you’ll want to regularly check your loft starting in the autumn anyway, just in case! Once you head up there with a torch, you’ll be able to tell fairly quickly whether there’s anything there – cluster flies are attracted to any light source so they’ll probably swarm you! This is unpleasant but the flies are harmless, so make a hasty retreat and start planning how you can deal with them.

As cluster flies are so small, they can easily slip through voids in your wall and into other parts of your home. This means you might also see a few of them gathering around windows or buzzing next to light fittings.

Dealing with Cluster Flies

Because your average cluster fly swarm will be made up of thousands of flies, you’ll need several methods of attack to make sure you get rid of every last one. Their strength in numbers makes them a unique pest, so you’ll need some unique pest control products to deal with them all. Luckily, you’re in the right place!

Automatic Aerosol Dispensers

Arguably your best defence against any flying insect is a regular aerosol spray. Our Prevent Auto spray contains an eco-friendly natural insecticide (pyrethrum, which comes from chrysanthemum daisy flowers) which attacks the brain functions of the flies. The aerosol disperses the insecticide into every corner of your attic, where it knocks down flies and kills them almost instantly.

The only problem is that one spray isn’t going to do much against a thousands-strong swarm of cluster flies. That’s why you should partner a can of Prevent Auto with an automatic aerosol dispenser for the best results. You can program the dispenser to spray insecticide at regular intervals and leave it to work its magic for a few hours or even days. This will significantly thin out the swarm and make it easier for your other pest control products to mop up the rest!

Electric Cluster Fly Killers

Regular electric fly killers will still kill cluster flies, but they’ll end up overwhelmed quite quickly. They don’t have very deep trays, so you’ll need to constantly go up and empty them or the fly remains will start to pile up, potentially posing a fire risk if they come into contact with the electric grid. A cluster fly killer comes with an extra-deep catching tray and a high-capacity zapping grid so they can deal with the thousands of flies in a swarm. You’ll still need to empty the tray when it gets full, but this will only be once every few days as opposed to every few hours.

Smoke Bombs

Smoke bombs are great for getting rid of most insects, and cluster flies are no exception! The smoke reaches into every corner of your loft space and penetrates any cracks in walls or flooring where the pests might be hiding. When combined with an automatic aerosol and an electric fly killer, it’ll thin out even very large swarms incredibly quickly.

The smoke inside a fumer contains an insecticide to quickly kill the insects while also driving any survivors out into the open. In our smoke bombs, this insecticide is pyrethrum, a natural ingredient which isn’t toxic to humans or animals. It also doesn’t leave any lingering smells, so you’ll be able to use your loft again within the space of a few hours!

Preventing Cluster Flies from Coming Back

The flies will move outside to mate in summer, but it’s important to wipe out every last fly in a swarm while they’re still in your loft. If you miss any, those survivors will leave a pheromone trail that leads right back into your home and the swarm will be back once they’ve built up their numbers again (we’ve said this a few times now, but it’s so important it bears repeating!). This is the best way to ensure that you aren’t left back at square one next year, so it’s always a good idea to re-treat your loft a few days after the initial treatment. Do this even if there aren’t any obvious signs of cluster flies around – if there are only a small number left in your attic, they can be quite easy to miss.

For more detailed advice on how to get rid of these pests, check out our blog on how to get rid of cluster flies.