How to Avoid Cluster Flies

Cluster flies are common throughout the UK, although they’re mostly found in rural or semi-rural areas. They’re active around people’s homes during the springtime as they emerge from their winter hibernation, and they can become a pest.

They can be tricky insects to keep out of your home, but you can take a few simple steps to try to prevent an infestation. For everything else, you will need a professional East London pest control expert.

Cluster Flies

What Are Cluster Flies?

Cluster flies get their name from their habit of clustering together in large numbers and hibernating in buildings. They’re slightly larger than the common house fly, and fairly sluggish when flying.

During the summer and autumn, they’re technically field flies and are no hassle to homeowners. In the winter, they hibernate indoors, seeking out cool, dark spaces such as lofts and basements. While they may look alarming due to their large numbers, they pose no threat to homeowners.

It’s springtime when they are at their most annoying. In their attempts to find their way back outside, they often end up in large, sunny windows and conservatories – in huge numbers.

How to Prevent Entry

In reality, it’s very difficult to prevent cluster flies from getting into your home, as they can squeeze in through the tiniest of cracks. But you can limit their chances.

Firstly, check all caulking around your windows and doors, and reseal where necessary. Prevent access into cavity walls by checking for gaps around service pipes, and other obvious access spaces.

Pay attention to your roof by looking for gaps in the eaves or fascia boards, and check you don’t have any ill-fitting slates or tiles. Also, ensure that your roof ventilation grills are insect proof.

How to Deal with an Infestation

A cluster fly infestation is problematic due to the difficulty of accessing their hibernating places. If you see cluster flies in your loft over the winter months, spraying with a good-quality fly spray will kill any flies it touches, although it won’t kill any hibernating in the cracks.

If you feel confident, you can use an insecticide fumer which gives off a thin veil of smoke that penetrates all the cracks in your loft. However, you must be sure that you don’t have bats or bees in your loft before you do this, as destroyed them is illegal. It’s also worth warning the fire brigade first in case your neighbour sees smoke coming from your roof and dials 999!

It’s often easier to call in professional pest control experts who have the equipment and experience of dealing with this sort of infestation. A pest control technician will inspect your premises and decide upon the best method of control.  Using a powered ultra-low volume generator, they will disperse an insecticide in the infected area.

After the treatment, the flies will initially become very active, then start to die off within a few minutes.

It’s worth noting that treatment is only effective for the current infestation, and it will not prevent the flies from returning in the future.

Erin Emanuel