The Exception?

What's the difference between a butterfly and a moth?  There is no simple answer. Butterflies fly by day and moths fly at night. Except for the day-flying moths. I discovered today that there are more of these than there are butterflies. Butterflies rest with their wings closed - some of the time, whereas moths rest with their wings open. Mostly. This Purple Thorn Moth contrarily rests with its wings at an angle.