Had a couple of them the last two days that would not go out of the back door, south facing so normally whatever flies in does a U turn and goes back or, if not immediately, eventually. One did get out and immediately did a U turn back. My clean disposal method of annoying ones is the hand held vacuum but neither of these would oblige so eventually each whacked with a hand whilst on a window, even then it had to be a window with central bar to limit its ability to dart out if the way.