In the summer months we frequently try and kill mosquitos in our home. They are tremendously skittish and get airborne pretty quickly as you approach them. However, if they land on a piece of glass (a window for example) they don't seem at all bothered at you approaching from the other side and tapping the glass where they have landed.
Is this some strange physiology of insects (or at least mosquitos) that they cannot look down? Is it that their eyes function differently to our eyes and cannot see through the glass? For sure, their brains cannot be developed enough to understand the safety afforded by the glass.