The word "mouse" in Oracle Bone Inscriptions is like a little mouse biting with its mouth open; In the process of evolution and development from Shang Dynasty to Qin Dynasty 1000 years, the pictographic mouse character has undergone great changes and has become linear in Xiao Zhuan in Qin Dynasty. The mouse character in official script evolved on the basis of official script. The head of the mouse has become square, and the feet and tail of the mouse are still pictographic, but the image of the mouse is not obvious. The mouse character in regular script absorbs the characteristics of the mouse character in official script, which is the word "mouse" used today, and cursive script is more common in artistic calligraphy and painting works.
Archaeological discoveries near Anhui province show that rats have lived on the earth for more than 47 million years before human beings appeared, which can be said to be living fossils.