My fruit fly 'community' is becoming problematic! At first there was about 100 of them, maybe even less. Now I'd say there's about 500 of them. I don't store old banana skins now and uneaten bananas are kept in a sealed, clear plastic bag. The flies missing the bananas and their skins have now moved onto my empty beer bottles. I know it sounds daft, but when I open a beer bottle they suddenly appear and mass on the kitchen cupboard door above the beer bottle. After a few minutes they start landing on the bottle and my glass. I have to cover both with things available like envelopes etc. I've had enough of them now and want shut. I tried leaving a banana skin on my outside window ledge yesterday while I went out. I left my window open hoping they'd all go for it and leave my kitchen, but when I got back 4 hours later not one fly was on the banana skin! All of the @'~#rs were still 'hanging out' on my kitchen cupboards. I don't want to use fly spray on them as they aren't really that annoying, but what else can I do?🤔