Notice: Constant WP_MEMORY_LIMIT already defined in /var/www/html/wp-config.php on line 136 How to Get Rid of Cluster Flies: Control & Prevention Guide

How to Get Rid of Cluster Flies: Detailed Identification & Removal Guide

Homeowners often encounter large numbers of cluster flies in late summer and autumn. At this time, these insects are the most active, as they seek refuge for the winter. Their number in the house will grow and increase if nothing is done.

I faced this problem myself and tried to understand how to get rid of cluster flies. But it’s not so easy if you use the wrong methods. Read this article about cluster fly extermination. Below I’ve described the proven methods and anti-fly remedies that helped me.

What Are Cluster Flies


Cluster flies are of the Pollenia genus in the Calliphoridae family. They are distinguished from ordinary room flies by their increased size and unusual body color. Cluster fly life cycle is a little more than one month, but in this short period, they have time to get tired of homeowners.

The body of insects has a golden hue with black stripes. Due to their body length of 7-8 millimeters, they are not very mobile, so they can easily be seen by a loud buzzing.

Cluster flies in houses are not aggressive. These insects do not set aside larvae for human food, so they pose a minimal threat to homeowners. But their presence indoors is disgusting.

They usually bunch up in large numbers in places that are difficult to access (the breeding ground often depends on how long do cluster flies live in the house). It is, therefore, essential to exercise cluster fly control to prevent the larvae from infecting the premises.

How Do Cluster Flies Appear in Your Home

Many homeowners do not know what are cluster flies or how they appear in houses. These insects enter the house through small openings, open windows, and doors or ventilation ducts. These insects cannot exist in cold and humid environments, so in autumn, they look for shelter for the winter. Dry and warm shelters for them are people’s homes, namely roofs, cellars, closets, and other hard-to-reach places. You don’t need to do anything to make your home a hiding place.

Signs of Cluster Flies Infestation

You need to make sure that your home is infested with insects before preventive treatment and cluster fly elimination. Their larvae are not dangerous to humans, but due to inaction, they will reproduce indoors continuously.

old Pollenia

The main sign of cluster flies in the house is the black spots on windows and other objects in the house near heat and sunlight. These insects love sunlight, so they spend a lot of time near windows, leaving their excrement behind.

You can detect the presence of flies by an unpleasant and loud buzzing in hard-to-reach places. If you see a large sedentary fly with black stripes on its body, it means cluster fly infestation. If there are many flies in the room, you find black spots on the lights, which causes inconvenience and the need to clean the house constantly. Dead flies attract other insects, which often cause spiders, mice, or rats in the room.

How to Get Rid of Cluster Flies

There are many ways to get rid of cluster flies:

Choose a means depending on how many cluster flies you want to destroy and where they live. I use concentrate or aerosol for cluster fly treatment on large areas and for the facade of the house. The alternative is sticky tapes or cans of sweet water in which the flies sink (they come down to sweetness).

You can also use electric boxes with UV lamps. Light attracts flies, which fall on the grid with electrical current.

In this article, I will describe several products of different kinds that are most effective against the sweet flies.

Top 3 Cluster Fly Treatments

I prefer to use insecticides in the form of aerosols or concentrate for getting rid of cluster flies. Choose the option that is more convenient for you!

1. Rockwell Labs LGL 016 Lambdastar UltraCap 9.7% – Effective Insecticide Concentrate to Get Rid Cluster Flies


  • Active Ingredient: Lambda-Cyhalothrin 9.7%
  • Item Form: Spray
  • Item Weight: 1.26 pounds
  • Item Dimensions LxWxH: 2.05 x 4.25 x 7.85 inches
  • Target Species: Ants, Bedbugs (adults and nymphs), Bees, Boxelder Bugs, Carpenter Bees, Carpet Beetles, Centipedes, and others

I prefer to use concentrated insecticide to get rid of severe insects infestation. Rockwell Labs LGL 016 Lambdastar UltraCap 9.7% is one of the best poisons I have ever used against flies. The chemical agent Lambdastar UltraCap 9.7% is easily mixed with water and sprayed around the house and in places where there are the largest concentrations of flies. Insects die immediately and will not appear in your home afterward.

I noticed the effect the next morning after processing the eaves, window frames, door sill, perimeter of the house, and attic. The product is safe for humans if you follow the rules of its use (gloves, goggles, and a protective mask). A 16 oz bottle will last a long time.

  • big, economic packaging;
  • efficiency against all insects;
  • momentary effect.
  • you need to stir it yourself.

2. CB-80 Contact – One of the Best Aerosols Against Cluster Flies


  • Active Ingredients: Piperonyl Butoxide 4%, Pyrethrins 0.5%
  • Item Form: Aerosol
  • Item Volume: 17 fl. oz.
  • Item Weight: 1.3 pounds
  • Item Dimensions LxWxH: 2.7 x 2.6 x 9.35 inches
  • Target Species: Fleas, Bedbugs, Silverfish, Ants, Flies, Cockroaches, Spiders, and others

I use CB-80 Contact spray if I need to treat small surfaces in the house against cluster flies. It contains an insecticide that instantly destroys insects. The active ingredient in CB-80 Contact is Piperonyl butoxide 4% and Pyrethrins 0.5%. Due to the thin and long atomizer, the chemical components get exactly to the target.

CB-80 Contact Aerosol 17 oz

Apply aerosol in places where flies live and breed. Within one day, they will die, and all you have to do is clean up. It’s enough to spray for about 10-20 seconds. But don’t forget to use a protective mask and safety glasses.

  • quick action;
  • effective against bugs, cockroaches and other insects;
  • safe for humans and pets.
  • not effective in open spaces.

3. ASPECTEK Upgraded 20W Electronic – The Best Zapper for Getting Rid of Cluster Flies


  • Material: Aluminum
  • Power: 40W
  • Item Weight: 4.71 pounds
  • Item Dimensions LxWxH: 25.6 x 3.5 x 12.8 inches
  • Target Species: Fly, Moth, Mosquito, Wasp

ASPECTEK Upgraded 20W Electronic is an electronic lightning bolt that destroys all insects in the affected area. A small device is enough to install in the office or home and plug into an outlet.

Light from UV lamps attracts insects, and a 20W electrical discharge will destroy them. Don’t worry, pets won’t be able to get a discharge due to the protective outer grid. All dead flies fall into a special box where they can be easily taken out.

I use this zapper when I don’t want to keep spraying insecticides.

  • effectively kills insects;
  • safe for pets and humans;
  • silent.
  • it’ll take time to destroy insects.

How to Prevent Cluster Flies in Future

Getting rid of cluster flies starts with preventive methods. Insects enter the house through cracks, open windows, vents, and cellars. Make sure it’s all been closed.

You can hang mosquito nets on the windows, just like on other openings in the house. In the attic or the basement, it is better to always hang sticky tapes against flies to destroy them as soon as they get inside.


Pollenia on the leaf

What causes cluster flies in house?

The flies die of cold and dampness. Therefore, with the onset of autumn, they seek a warm and dry refuge that your home can become with the onset of cold, other small insects that the flies feed on the move to warm rooms — for example, worms and larvae.

Will cluster flies eventually go away?

Cluster flies can indeed leave your home with the advent of warmth. But you will have to winter with them for several months to do so. Are you ready to tolerate the annoying whirring and black spots on windows and lights? Besides, even one day with big flies is unbearable!

So I would not recommend you to wait for the insects to leave home themselves. In a few months, they will put off thousands of larvae, of which there will be new insects. It’s an endless circle!

How to get rid of cluster flies without pesticides?

There are simple ways to get rid of cluster flies without pesticides. This is acceptable if there are few insects in the house, and they do not disturb you too much. First, make sure that flies can no longer enter the room.

Make sure there are no cracks in the facade of the house and that the open windows are protected with mosquito nets. Then use tried-and-tested methods: hang a special adhesive tape or put a can of sweet water on the table. Gradually, flies will fall into the water or stick to the tape, dying from it.

How do you get rid of house flies fast?

The fastest way to get rid of flies is to use insecticides. Use tested aerosols or chemical concentrate to get rid of these insects and their larvae forever.

Now You Know How to Get Rid of Cluster Flies

Now you know the answer to the question “where do cluster flies come from” and ways to destroy them in your house. When using insecticides, remember to use personal protective equipment. This way, you can destroy insects in just a few days. But before you do that, you will have to determine where they enter the house and where they put their larvae.

Most importantly, you know the three best products for destroying insects. Use concentrate, aerosol, or zapper, depending on your personal convenience and other vital factors mentioned above.


  • Cluster Flies (Ubico Limited):
  • Cluster flies (Coventry City Council):
  • Cluster Files (Cornwall Council):


Why You Should Trust Pest Control Hacks?

We know that pests are nasty neighbors, and it can take months to eliminate them without the right approach. Our experts use their own experience to compile articles and guides that are introductory and informative. Our authors’ opinions are independent and based on the results of practical testing of pest control tools. We do not notify manufacturers of testing of their products and do not receive payment from them for posting their items. Also, our texts are never submitted to company representatives for proofreading before placement. On the site, you will find exclusively objective ratings and reviews.

Nicholas Martin

Nicholas Martin

I am Nicholas Martin, and I am an entomologist. I combine the insect survey work with the consultation for private pest control agencies. My narrow specializations are both urban pests and agricultural pests. I studied their control over the previous 25 years. More about Nick

We will be happy to hear your thoughts

      Leave a reply

      Solve : *
      24 + 27 =

      Pest Control Hacks