Tree squirrel Tree squirrel Tree squirrels are the members of the squirrel family (Sciuridae) commonly just referred to as "squirrels". They include over a hundred arboreal species native to all continents except Antarctica and Oceania. They do not form a single natural, or monophyletic group; they are related to others in the squirrel family, including ground squirrels, flying squirrels, marmots, and chipmunks. The defining characteristic used to determine which species of Sciuridae are tree squirrels is dependent on their habitat rather than their physiology. Tree squirrels live mostly among trees, as opposed to those that live in burrows in the ground or
Habit (biology) (free-living, parasitic, holozoic, saprotrophic, trophic type), type of habitat (terrestrial, arboreal, aquatic, marine, freshwater, seawater, benthic, pelagic, nektonic, planktonic, etc.), period of activity (diurnal, nocturnal), types of ecological interaction, etc. The habits of plants and animals often change in response to changes in their environment. For example: if a species develops a disease or there is a drastic change of habitat or local climate, or it is removed to a different region, then the normal habits may change. Such changes may be either , or adaptive. In botany, habit is the general appearance, growth form, or architecture. For example: Plants