As the name suggests cluster flies are a problem due to their preference to gather in large numbers – but what do you do if they move into your home or business? 

Cluster flies in themselves are not harmful to humans, so while the thought of these insects making themselves at home in your house or business may be unpleasant they will not actually cause you any ill effects.  

Looking like a normal housefly, expect for some tell-tale yellow hairs, cluster flies are slow movers that will fly languidly around your house and gather at the windows.  

The main way in which they differ from other flying pests is that they are a problem in winter. 

As heatseekers cluster flies will appear on the side of homes or at windows as they aim to bask in the warm rays of the sun.  

Cluster Flies UKFrom here they will quite often head into the attic – or even the walls of your house or business – as they look for a warm place to rest and hibernate before waking up in spring. 

Why are cluster flies a problem? 

Rather than being a threat to health, cluster flies are an annoyance, largely due to the fact that they gather in such large numbers. No home or business wants to be swamped by hordes of flies after all.  

Aside from their sheer numbers, cluster flies will also leave behind faeces, which can be seen as black spots on windows and walls. In addition, the flies create a distinctive smell. 

A huge problem with cluster flies is that once they are in your home there is a very good chance they will return as they leave behind a scent that they return to.  

This means that dealing with the problem and taking action to keep them out of your home is important.  

Getting rid of cluster flies 

There are a number of methods that can be used to try to control the numbers of cluster flies in your home such as fly sprays, putting up fly screens and vacuuming the flies 

Cluster Flies UKBut in the event of suffering an infestation you will need to call in expert help to ensure that the problem is dealt with properly.  

Insecticide may need to be used but it is important that a thorough check is made to ensure that there is nothing in the home that may be adversely affected, such as bats which have protected status.  

In the event that the cluster flies are killed, or die, within the house further action may be needed to help clear the dead flies as these can lead to further problems by attracting larder beetles. 

Once the problem has been dealt with it is important to take steps to try to prevent cluster flies returning to your home by sealing gaps and installing fly sheets. 

Pest Busters can offer expert help in the control of domestic pests including flies, insects and rodents 

If you suspect that you may have a problem in your home with cluster flies please contact Pest Busters to find out how we can help. 


Pest Busters (Birmingham)

Highfield Farm, Middle Lane, Kings Norton, Birmingham B38 0DX
0121 695 9076