The external appearance of a baby squirrel offers few obvious clues to distinguish between a male and a female. This is especially true for very young pups, often called “pinkies,” who are under four weeks old. Accurately determining the sex requires a careful, close-up examination of the anatomical structures located beneath the tail. The most reliable method focuses on a specific measurement and the distinct shapes of the two openings in the lower abdomen.
Essential Preparation and Safe Handling
Handling any wild animal, even a small baby squirrel, requires careful preparation to ensure the safety of both the animal and the handler. Before attempting examination, confirm the squirrel is warm and calm, as a cold or stressed animal should not be handled. If the baby squirrel feels cold, postpone the examination until it is safely warmed, often using a heating pad set to low with a protective towel barrier. Always wash your hands thoroughly before and after touching the squirrel, as they may carry parasites or pathogens.
To perform the check, gently restrain the baby squirrel using a soft cloth or a small towel. This material provides a gentle grip and helps the animal feel secure while minimizing direct skin contact. The examination should be conducted quickly and calmly to reduce stress. Once the sex has been determined, immediately return the squirrel to its warm and safe environment.
The Primary Method Anogenital Distance
The most dependable method for sexing a baby squirrel involves comparing the distance between the two openings beneath the tail. These two openings are the anus, closer to the tail base, and the urogenital opening, located below the anus. The space between these two points is known as the anogenital distance, a measurement that differs significantly between sexes.
In a male baby squirrel, the distance between the anus and the urogenital opening is noticeably longer, creating a distinct gap. The male’s urogenital opening often appears as a small, rounded dot or a slightly raised nub. This extended gap is a consistent feature that remains reliable even in hairless, neonatal pups.
Conversely, female baby squirrels display a much shorter anogenital distance, with the two openings positioned very close together. The female’s urogenital opening (the vulva) typically presents as a vertical slit or a linear dash just below the anus. The close proximity of these structures is the clearest indicator of female sex.
Secondary Visual Cues and Confirmation
While anogenital distance is the definitive method, other visual features can offer confirmation, particularly as the baby squirrel matures past four weeks of age. The shape of the urogenital opening can serve as a secondary identifier: the female opening is generally a vertical slit or tear-drop shape, resembling a line. The male opening, in contrast, is smaller and rounder, appearing more like a dot.
The presence of nipples provides another helpful clue, though this is only conclusive if they are present. Female squirrels have eight teats, which typically become visible around the three-to-four-week mark. If small nipples are clearly visible on the lower abdomen, the squirrel is female.
The absence of nipples in a very young pup is not a guarantee of maleness, as they may simply be too young for the features to be apparent. In older male babies, the scrotal sac may begin to develop. However, because male squirrels can retract their testicles into the body cavity, a visible scrotal sac may not be consistently present until they are several weeks old.