Elected in 1914 to represent a school of ambitious engineers, the beaver mascot has been embraced by every subsequent generation of MIT students. One of the secrets of its success is its enduring appropriateness as a symbol of the community. Originally chosen for its engineering skills, industriousness, and nocturnal habits, the North American beaver has not changed much over the century, but its likeness on campus morphs from generation to generation.
One of the enduring platforms for the MIT beaver is the school ring, affectionately dubbed "The Brass Rat." Although the design changes from class to class, the beaver has consistently adorned the MIT ring since 1929.
Use of the beaver is restricted to the Brass Rat and to the MIT Department of Athletics, Physical Education and Recreation.
"So we turned to Mr. Hornaday's book on the animals of North America and instantly chose the beaver....The beaver not only typifies the Tech man, but its habits are peculiarly our own. Mr. Hornaday says, 'Of all the animals in the world, the beaver is noted for its engineering and mechanical skills and habits of industry. His habits are nocturnal, he does his best work in the dark.' "
— Lester Gardner, Class of 1897