The majority of ground and tree squirrels are diurnal, meaning they are active during the day and sleep at night. Flying squirrels, however, tend to be nocturnal and are active at night.
There are many different kinds of squirrels, but most squirrels, such as the gray squirrel, red squirrel and fox squirrel, build their dens in the sides of trees while ground squirrels typically dig dens underground. A common squirrel den will be outfitted with moss and...
At night, squirrels conclude their activities by retreating to nests, which are primarily built in trees. Like birds, most squirrels build nests to serve as homes, which they use for raising young and resting. Many construct their dwellings on tree branches, although so...
Squirrels take refuge in dens and nests in the wintertime. Like humans and many other mammals, squirrels need protection from the harsh winds and elements of winter. Their wintertime shelters vary in size and composition depending on location, but all contain overhead r...
Squirrels primarily eat tree nuts, seeds and fruit, but their diets can also include flowers, bark, eggs, insects, leaves and even baby birds. Squirrels are opportunistic feeders, which allows them to consume human garbage when none of their favorite foods are available...
Squirrels live on every continent of the world except Antarctica and Australia. However, in recent years, squirrels have been introduced to Australia.
According to Live Science, most fish species do sleep, although their sleep cycles are different from human or mammalian sleep. Certain shoaling species that never stop swimming may never sleep.