Oh my word. I don't know what's going on. I've got circa 25 flies in my dining room. And there's more appearing in other rooms. They're big and fat and horrible. I've got one of those zap-insect things on (the blue light thing) but they're ignoring it. What is going on? I've no fly spray and friends coming for lunch any minute. EEEEEEEEEEEEEk.