A loft full of flies

[d000hg]

Still visiting my late parents' house. When I arrived I noticed a LOT of flies in a couple of windows (like 20+ in each); dead or sluggish bluebottles. I killed them and hoovered them up and thought little of it.
For the next few days, I kept finding 2-10 new dead flies by one window with no obvious place for them to come from.

Today I had a quick look in the loft (it's got a fixed staircase and is very large). I didn't dare go up because looking up from the bottom of the steps with a torch I could see dozens of flies clustered on the roof... I fear if the rest of the roof out of sight is the same there may be hundreds or more. they're not flying around just sitting or wandering about. Pretty gross... I daren't go up in case they swarm me!

Thinking about it I can remember finding a few dead flies all the time when I visited in the past, maybe they were getting cleaned up as as as they appeared so I never noticed.

What should I do? I'm only here today and have no car so I'm limited. The house is for sale and I'm worried as it warms up, anyone viewing the place and going into the loft will get a a horror-film experience they weren't after
Could I just spray a whole can of Raid up there? Should I ask someone to get a bug bomb and just chuck it up the stairs? Do I need to bring in a pest-control guy? If this has been going on for some time they've clearly been breeding multiple generations which implies eggs... and maggots. Lots of maggots. As well as it being gross I'm concerned what they might be eating, whether it's just some dead bird/mouse or they might be feeding on the beams or insulation or something!

 

[Grenage]

If it's bluebottles or the like, it is, as you say, down to a dead animal. Only one way to deal with that, really - locate the source.

Was there ever a mouse problem? Don't worry about them eating the structure, you're safe there.

 

[d000hg]

We have had some mice though not loads... one could easily have died up there. Though by now I'd have thought it would be mostly eaten!

I definitely don't want to deal with that... I have a full can of fly spray so I think I'll keep squirting that up then venture up the stairs when it looks quiet. If there's a mound of flies on something I can at least squirt them as a short-term measure until I can find someone to sort it.

 

[bernardgreen]

Your only option is for someone to go into the loft and locate the food source for the flies. Remove it and spray or otherwise destroy any remaining flies and / or maggots.

If it is a terraced or semi detached house the food source may be next door and the flies using gaps in the party wall to get into your loft.

Some local councils have Pest Control Officers who may be able to help you.

 

[Mottie]

Perhaps they are swarming and building a nest. You gotta find the queen fly and kill her. She'll be in the middle of the biggest ball of flies.....

 

[chris1982]

aren't you thinking of ants?

 

[d000hg]

Or wasps. If I could figure out how I'd glue the button down on my fly spray and toss it into the roof

 

[Mottie]

Heyyy. I'm joking!

 

[foxhole]

Must be a dead rat in the loft , they climb the drainpipe with ease and love loft insulation.

 

[Doggit]

The easiest solution is a couple of bug bombs. You push the knob down, and it locks into place, and starts spraying. Open the hatch door, set it going, and place it (or them on a joist where they won't fall over. Close that hatch, and then leave it for a day.

I use sulphur to get rid of fleas and bugs, which is much cheaper though. You pour a spoonful or so into the base of an upturned coke can, and then light it with a match, then close the doors and leave it for about 12 hours.

 

[KenGMac]

d000hg, good evening.

Blue bottles, I believe correctly called Blow Flies love cadavers as a source of food and laying eggs, Etc. Etc. Etc.

What would tend to occur is that an animal dies and the Blow Fly Cycle starts, that Cycle will terminate when the Cadaver is exhausted, in that it in effect becomes petrified, no longer a source of nutrient to the Blow Flies.

Such is the way of the world, I have tried to sanitise ? the above?

What is of curiosity, is that if there were one or two Cadavers they should have petrified and of no ongoing food source? especially a couple of mice even one or two rats, the food source available is limited?

It would appear that there is something infesting the property then in the natural way of things [Sanitised again] the blow Flies take over.

Have you seen any indications of Mouse infestation, or dare I ask Rat infestation?, look for droppings in corners under units, inside units Etc.

Have a look from the outside, are there any obvious bird Entry points, asking because if say pigeons are entering these birds carry a very high Veterinary morbidity load, lots of different diseases knock them off quite quickly. if there is an ongoing invasion of Roosting pigeons then that could be the food source that the Blow Flies are concentrating on?

I have over the past ten days knocked down three Rats that were happily feeding on my hens Layer pellets in the back yard, i set up a bate trap and chucked some rat poison down a rat hole that i eventually located, unfortunately I am not allowed under Scottish Air Weapon rules th shoot them with My Air Rifle, even on my own land it is against the law up here, shooting would have to be a better option than Poison?

So where are we? long term on going blow Flies, look for food source, eliminate food source no more Blow Flies. As an aside entering the loft even with flies floating around is no great danger, the temperatures are low at present so they will be sluggish, if possible choose an early morning after a very cold night, the Flies will be slow and sluggish? Set the bug sprays and withdraw.

After lunch have a look??

Ken.

 

[Bosswhite]

There`s a dead body up there somewhere, if fly spray dosent work call in the Police. !!

Have you checked on your neighbours lately

 

[Mikefromlondon]

A possibility that a dead bird or a small animal has died in the loft water tanks and floating near the surface, water is also essential to breeding, as dead animals can dry up in loft draft, so quite possibly you may even have highly contaminated water supply. I wouldn't rest until the source is traced.

Onece a time, a mate of mine picked up a reasonably good looking Vax vacuum cleaner dumped by someone on a pavement and brought it to me, he said if it works I can keep it, I thought nothing of it, it looked quite like a new, and it even worked! except it had been used as there was dirt in its dust container.

I didn't really need it, so I left it in my loft, then about a month later I started to notice these strange flies they fold their wings and appear like small brown sticks, about a cm in length and about 2mm wide, at first there were just a few, and thought nothing of them, next day I noticed there were half a dozen, following day a lot more, if you disturb them they would fly off and land a short distance away and go to rest again, so this continued and and I could not understand where they were coming from, my loft hatch was open, as it was in a property undergoing renovation, then I decided to use that same vacuum cleaner to suck them all up, as I brought it down, I noticed how these moth like flies started to emerge out , so this was the source!

 

[d000hg]

Good call about possible water tank issues, luckily not the case here but I've heard nasty stories!

How long might one dead mouse/bird last I wonder? The fact I only saw dead or dying flies... Drawn to the light at windows... Makes me think they might be starving? Very lethargic like winter wasps.

 

[JohnD]

It sounds to me like cluster flies. They tend to congregate in lofts.