Not sure if this is the right area to post... but here goes
Since moving in we seem to be having an increasing problem with flies.
Literally hundreds of them (blue bottles and houseflies I believe) are congregating in our bathroom. They aren't flying around or buzzing but rather sitting about on the window, curtain, shower curtain, bath, tiles etc. - like they are waiting for a very important meeting to start!!! There are a few flies, ie 1 or 2 in other parts of the house (which you would expect)- but the bathroom is starting to look like something out of a horror movie.
The bathroom is clean and obviously there is no food left around in there - also it doesn't smell like the drains need doing.
We have tried spraying and zapping them with an electric bat like fly killer and also putting an ultra violet light zapper in there - all of this works for a few hours, but once we stop they re-appear in masses.
Does anyone have any ideas as to what might be the cause and how to get rid of the little blighters?