This is a periodic problem I've been having with ArcMap. When beginning a new map the program auto-generates a legend, scale bar, and north arrow. The scale bar and north arrow are selectable and easily removed, but the legend isn't. As I add layers to the TOC the legend grows, peaking out above the map in layout view (see attached image). I've been working around it by simply covering it up with a rectangle, but wondering what is causing this?