On sunny days we open our back door and are in and out of the garden, which is so lovely. The downside is that flies get in but don’t seem to know how to leave. It’s disgusting. Does anyone have any tips about how to stop them getting in? Or what I can do to get them to leave? Is the only solution to kill them? I don’t really want to do that but ultimately they die anyway as they can’t get out. Obviously I waft them out wherever I can but I’m ludicrously outnumbered. Please help!