The Eastern University Affiliated Hospital, being an adjunct to The University of Tokyo's Medical School, naturally has work related to medical and pharmaceutical research, and laboratories are, of course, an indispensable part of the setup.
Inside the laboratory, a group of white mice scurried about within cages made of transparent resin, squeaking intermittently, in their search for food to fill their bellies or something to gnaw on to wear down their ever-growing incisors and thereby avoid starving to death from their teeth getting too long.
But obviously, the white mice used for experiments usually don't live long enough for their incisors to grow to the point where they lock up their mouths; they get disposed of because of various experiments, turning into non-recyclable waste. Even some white mice used for drug experiments require special incineration disposal.
