The community is broken up on the approach of winter, the males and workers perish, and the young queens after hibernation start fresh nests in the succeeding year.
They are born blind, but in a marvellously short period are able to cater for themselves; and their hibernation begins later in the season than with the adults.
There was little hibernation in the town often called the Switzerland of America.
The hibernation of these rodents is only partial, and confined to seasons of intense cold.
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.
For safety during hibernation and moulting, book-scorpions spin a small spherical cocoon.
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.
Limit on the permanently frozen underground, where hibernation is of course impossible.