flies lurking in window frames

Since we installed UPVC double glazing a couple of years ago, we've been troubled by flies -- presumably of the house variety -- attempting to hybernate in the grooves* of south-facing windows -- mainly on the first floor. The result is that when, in late autumm or early spring, a window is opened anywhere from a dozen to a hundred rather dozy flies tumble into the room, wake up, and start buzzing around. A quick blast w/ a suitable insecticide normally deals with them, although the resultant task of finding and disposing of their remains isn't exactly a favorite job :-(
Any suggestions for getting rid of them? For some reason the spider population that patrols the other windows on the property (all those facing north or west) doesn't seem to like the south side of the house after the change of the windows (the previous single-glazed, wooden frames seemed to be suitably spider-friendly, independent of position).
Julian
* for clarification, the main concentrations seem to be within the space between the window frame itself and that part of the window surround that sits proud of the plane of the frame.
--
Julian Fowler
julian (at) bellevue-barn (dot) org (dot) uk
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I'd be interested in this, too, since we have exactly the same problem.
--
"The road to Paradise is through Intercourse."
[email me at huge [at] huge [dot] org [dot] uk]
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Huge wrote:

I wonder if these might be "cluster flies"? Do a google on this phrase in the newsgroup or on the web. tony
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On Mon, 02 Feb 2004 13:18:49 +0000, Julian Fowler

Probably cluster flies.

Cluster flies come up every now and then on this n.g. - I was involved in a thread or 2 a few years back.
Try a google search?
Tim Hardisty. Remove HAT before replying
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