Newly ear-notched mouse in Optimice cages, TAFE classroom

Optimice housing units used in laboratory setting and in TAFE/educational facilities with animal courses. Mice may sometimes be provided a toilet roll as "enrichment," otherwise they are provided only food, water, litter, and a small amount of bedding material. Each cage is used to house up to 6 adult mice at a time, and kept in a large rack that can contain dozens of cages.

Mice are "ear notched" for identification purposes (holes are punched in their ears in areas that correlate to a number system). This is done without any pain relief, despite less invasive alternatives such as dye marking and fur trimming being well known and similarly effective.

These young mice have been bred as part of a TAFE course, with one cage containing as many as ten 3-4 week old babies, and their parents. The parents are brother-sister inbred, and have been for at least 20 generations. Because mice can become pregnant as soon as they give birth, leaving the male in the cage results in back-to-back breeding, which can cause serious health issues for the mother and subsequent litters.

The babies pictured have just had holes punched in their ears for the aforementioned identification purposes. During this process, they were scruffed, and they struggled and vocalised in obvious pain and fear. In the photos, they huddle together in the corners of the cage. These mice will be used for breeding, and to train veterinary students to give injections and other procedures. When no longer useful, they will be killed using a Co2 gas chamber (proven to cause distress and pain in mice).