"Where do butterflies spend the night?
At night, or during inclement weather, most butterflies perch on the underside of a leaf, crawl deep between blades of grass or into a crevice in rocks, or find some other shelter, and sleep.
How do butterflies spend the winter?
In areas where temperatures drop below freezing during part of the winter, at least one stage in a butterfly species' life cycle must be resistant to freezing if the species is resident. Most butterflies that live in cold climates spend the winter as caterpillars, while almost as many spend the winter as pupas. A few species, mainly tortoiseshells (Nymphalis) and anglewings (Polygonia), spend the winter as adults, hibernating in holes in trees, in crevices in man-made structures, or in other shelters. A very few species spend the winter as eggs."