Do butterflies sleep or take brief naps?

When butterflies cannot keep their temperatures at activity levels, when it's cloudy, or at night they become quiescent. This quiescence, or resting, is not equivalent to human sleep. Butterflies always have their eyes open, since they do not have eyelids and they probably do not dream. Certainly, I don't know of anyone who has heard of a snoring butterfly! It's probably best just to consider that they become inactive.