First of all, squirrels are not allowed to eat chocolate. Caffeine in chocolate has a fatal effect on squirrels. If the owner carefully feeds his squirrel chocolate, there is no way but to accept the result that his squirrel is about to die.
Secondly, onions are also very irritating to squirrels. After eating, it will cause great stimulation, destroy the hematopoietic function of squirrels, cause sepsis, and even make squirrels lose their lives.
Finally, apple seeds are unfriendly to squirrels, which will weaken their stomachs and cause symptoms of renal failure. If not treated in time, squirrels will die soon.
The earliest known squirrel species fossils come from Eocene strata. It is a long time from 65 million years ago to 35 million years ago. At that time, dinosaurs had just died out, mammals had not gained control of land, the Qinghai-Tibet Plateau had not become land, Europe and North America were still connected by land, and South America was a huge island.
The most primitive squirrel lives in North America, and its shape is close to that of today's flying squirrel. A series of fossils of squirrel species have also been found in the late Eocene strata in North America, which are different from any kind of squirrel.
The unusually rich fossil species of squirrels in North America indicate that the Squirrelidae originated in Eocene North America, and in the long years since then, it has radiated to all continents outside Oceania, and in the process, it has evolved species with different shapes and adapted to various environments.
Among the existing species of the suborder Rodentia Squirrel, Dormouse family mainly distributed in Eurasia and Beaver family distributed in North America are closely related to Squirrel family. Squirrel family is the most famous member of squirrel family, and it is also the most widely distributed and diverse group.