Abstract
Own experiences with the identification of mice and rats using ear tags, ear punching, toe clipping (for newborns only) and ear tattooing are given and compared with methods presented in literature. By far, ear tattooing by the newly developed pincers is the most suitable method for marking adult rodents for life. Tattooing is easy to apply, easy to read and not harmful to the animals. For newborn pups on day 4 p. p., the s. c, injection of India ink into the palm of paw is recommended.