Short answers, pulled from the story.
The word squirrel, first recorded in English in 1327, traces back to the Ancient Greek word skiouros, built from skia (shade) and oura (tail), a reference to the animals' long bushy tails. It entered English through Anglo-Norman esquirel and Old French escureil, derived from the Latin sciurus.
There are about 285 living squirrel species, organized into roughly 58 genera across five subfamilies. The family includes tree squirrels, ground squirrels, flying squirrels, marmots, chipmunks, and prairie dogs.
The Bhutan giant flying squirrel is among the largest, reaching up to 1.27 meters in total length. Several marmot species, which are also members of the squirrel family, can weigh 8 kilograms or more.
Some squirrels do eat meat, particularly when food is scarce. The thirteen-lined ground squirrel has been documented preying on young chickens and snakes, and in 2005 a pack of black squirrels in Lazo, Russia, killed and ate a large stray dog. Some tropical squirrel species have shifted almost entirely to insect diets.
The fossil and phylogenetic evidence points to North America as the likely origin of all squirrels. The oldest squirrel fossil, Hesperopetes, dates to the late Eocene, roughly 40-35 million years ago. The three most ancient living squirrel lineages all appear to have radiated from North America.
Adult squirrels in the wild typically live 5 to 10 years, though many juveniles die in their first year of life. In captivity, some squirrels have survived for 10 to 20 years.