Spiders Beware!!

I don't know about other people's experience of these little beasts, but the ones currently availing themselves of very comfortable accommodation in my house had better watch out!
Now I'm not to sure whether they are all on diets or what, but while they are lounging about, contemplating their navels (if spiders have such things) or knitting and crocheting new webs, I am being overrun with plagues of very small flies.
Already over the last few weeks I have used up a couple of aerosol cans of fly spray which I don't really like using and it doesn't seem to be that effective anyway. I have also tried squishing them in the windows with tissue and a latex glove and today even resorted to sucking them up in the vacuum cleaner!
This is a problem I have never had during the twenty five years that I have lived here and despite hunting everywhere I cannot find out where they are coming from. They have obviously come in for the warmth now that the weather is getting cooler but they are certainly very unwanted visitors.
Although I don't have that many spiders, if they ate all the flies they would probably be the size of tarantulas but nothing seems to entice them to tuck in. So, I'm going to issue you little beasts with a warning! If you don't keep the numbers of flies down I'm going to get out my feather duster and whisk your webs down, so there!!