As recounted in the old nursery rhyme, "Three Blind Mice", the farmer's wife cut off the tails of the mice with a carving knife for running after her, but did she know what she was slicing through? The tail of the mouse is composed of chondroid tissue, bone, tendon, muscle, and skin with hair follicles, as well as nerves and blood vessels.

As a tale of success, the mouse's tail is playing a key role in ongoing stem cell research and development of possible cures for spinal cord injuries. Geneticists favor the tail end of the mouse as a rich source of DNA isolates that are RNA free. The clipped tails of young mice can be successfully stored frozen until DNA extraction is completed, following well-established proteinase digestion protocols, without having to sacrifice the laboratory specimen. Mouse tail is used as a model of human skin in drug trials such as those of topical cream formulations for psoriasis, for cancer research, and is used in other experimental procedures because sampling blood from the tail vein of a mouse or rat is relatively easily carried out.

During embryonic development, approximately ten days following conception, a tail bud appears as a short stump, and then initiates elongation and thinning. The tail of a mouse or rat may be repulsive to some, but to the small rodent, it provides balance, and acts as an effective temperature regulator. As a distinguishing characteristic, the ratio of the relative length of the tail to the body offers rodent taxonomists a method of distinguishing closely related mouse species.