Found a few of these insects in our townhouse near the base of Burnaby Mountain, in Burnaby, BC, Canada. I was terrified that they are termites or carpenter ants but the more looking I am doing the more likely these look like a type of fly. I don't have a good photo of their wings outstretched unfortunately, my husband killed the last batch before I could get to it. We usually see 2 or 3 at a time and they have been coming and going for the last couple of months. We find them near the top of walls in our stairway between the ground floor and the second flood. They are not anywhere near a door or window. We do have an indoor worm composter but I haven't seen any bugs come out of that. The husband found a little hole between the wall and the stairs yesterday where he thinks they are coming out of. We share our house with a cat, no other pets. Any help in identifying this and dealing with it (do we need an exterminator, do they cause damage etc) would be most appreciated. Sorry the photo isn't better. I will try and get a better one next time we see one.