There was little hibernation in the town often called the Switzerland of America.
For safety during hibernation and moulting, book-scorpions spin a small spherical cocoon.
In Europe and North America the continued existence of species is ensured by the hibernation of impregnated females, or else the winter is passed in the egg or occasionally in the larval state.
The hibernation of these rodents is only partial, and confined to seasons of intense cold.
In both there are species which form no nest or burrow, others which construct a simple silk-lined tunnel in the soil, and others which close the aperture of the burrow with a hinged door; while both share the habit of lining the burrow with silk to prevent the infall of loose sand or mould; and the species which make an open burrow close the aperture with a sheet of silk in the winter during hibernation and open it again in the spring.