Dr. Johnny Roughan studied the welfare and scientific considerations of tattooing or ear tagging mice as a method of identification. The full paper can be read and downloaded here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6433351/
The conclusion of the study was "Overall, we conclude that there is probably little justification for
choosing ear-tagging over tattooing."
Below is an extract from the study, which specifically examined, and demonstrated, the accuracy benefit provided by reading Labstamp tail tattoos as a mouse ID method versus the widely used metal ear tags.