Is the main difference between butterflies and moths that butterflies close their wings vertically and moths close them flat?
You might expect that to be the case but it is not true. Skipper butterflies do not close their wings vertically, instead they rest with the upper wing open at an angle of around 30o. On the other hand, several moths of the Geometrid family, which is the one closest to butterflies in many respects, can close their wings vertically and in many other ways including colour can resemble butterflies.