What exactly do butterflies do at night? As they can't get any nectar and it's too dark to find a mate, butterflies choose to take their rest once the sun goes down. Butterflies don't sleep as we do, but they do enter a dormant state of inactivity as it gets darker and darker. They will find a safe spot hidden among leaves and bushes before they make their rest, often hanging upside down all night. Some species even choose to "roost" together in groups!