As winter bites we’re not alone in wanting to keep warm and dry in our homes. There are plenty of  other creatures seeking out our homes as a safe and comfortable refuge.

Pests such as queen wasps, queen bumblebees, ladybirds and Lacewings, field mice, rats and squirrels to name a few.

Pests cause strange noises in the home

The phone calls start in late autumn with reports of strange noises in ceilings and wall cavities. Problems with chewed plastic plumbing, fascia boards or lead flashing. The most worrying of all, chewed electric cables !

Although it is rare for rodents to cause a house fire by chewing through electric cables it does still happen so we obviously take it seriously. However, one wouldn’t imagine insects could potentially burn a house down.

Smoke alarm alerts caused by cluster flies

We were called out to a property recently by a concerned home owner reporting noises in the roof along with intermittent smoke alarm alerts. The obvious assumption was that a rodent had got in and was chewing away at the wiring. This was not the case though as there was evidence of recent mouse activity found, but the smoke alarms weren’t caused by wire chewing, but instead by cluster flies.

What are cluster flies?

Cluster flies are a member of the blowfly family. They are parasitic insects, the  larvae of which feeds on earthworms. However, they are not considered a health hazard in the way that a housefly or bluebottle is, as they don’t contaminate human food.  They are somewhat of a health hazard when they encrust themselves around a back of hot lightbulb though. 

When do cluster flies become a problem?

From September each year, cluster flies come off the fields and grasslands in search of a hibernation spot. They will seek out shelter in the cold months. Most commonly it will be a hole in a tree, or behind peeling bark. But they also love warm house walls, so those facing south or west. They can get into roof spaces and other crevices. You might find their faeces and other mess around windows, particularly in the window frame. If your windows are poorly fitted then it’s perfect for cluster flies to gather.

Cluster flies also love a nice cosy roof space. Once they’ve gained access to your loft then they will come in through light fittings.

They can be found in their thousands and once in will hibernate or winter down until things warm up in spring. Now the problems arise from the way we light our homes these days. Most of us have flush-fitting ceiling lights and it’s the top part of the fitting that is often exposed in a roof space. It is a nice warm spot for insects to nestle in, that is until they get fried and encrusted around the lamp. Smoke then drifts around, setting off the smoke alarms. Mystery solved! Simple…

How to get rid of cluster flies

The not-so-simple part is keeping these insects out. Unlike rodents they can get through the tiniest gap under a roof tile, between the soffits and fascia boards for example. This makes it impossible to proof against them. There are insecticide treatments available to eradicate them but a survey and risk assessment must be carried out first. After all, there may be other animals sharing the loft space, like bats for example. Bats are heavily protected and there is a hefty penalty if one should come to any harm through negligence. 

How to treat and prevent cluster flies

At Eradipest we have a range of pest control solutions for cluster flies. We will conduct a property survey which will identify gaps and places where cluster flies can get into your house. These include extractor fans in shower rooms and poorly fitted window frames. We will seal these up and also fumigate loft spaces. We will install electric fly killers in the loft and fit flyscreens over extractor fan outlets.

If you’re concerned at all, call us on 01243 717606 to book a survey with one of our experienced Technicians.