The 1st Computer Rodent
In 1964, Dr. Douglas Engelbart received a patent for a device consisting of a wooden shell and two metal wheels - the computer mouse. In 1970, a patent was awarded (out of more than 45 for Dr. Englebart) for what was described in the patent application as an "X-Y position indicator for a display system." He nicknamed it the "mouse" because the tail came out the end.
World's First Computer Mouse, by Douglas Engelbart
X-Y Position Indicator for a Display System
USPTO Patent #US 3541541 A