How do pregnant domestic rats look? - briefly
During gestation a pet rat’s abdomen expands into a round, firm belly, and the nipples turn pink and become more pronounced, especially in the later weeks. The coat may look slightly fuller, and the female often shows heightened nesting activity.
How do pregnant domestic rats look? - in detail
Pregnant pet rats display a series of unmistakable physical changes that become evident as gestation progresses.
The abdomen expands markedly, forming a rounded, bulging profile that distinguishes a gestating female from a non‑pregnant counterpart. The enlargement begins around day 10 of the 21‑day pregnancy and reaches maximum size near parturition.
Nipples, normally inconspicuous, become enlarged, pink, and more numerous, typically numbering between eight and twelve. The areolae may appear darker than surrounding skin and are easily felt through the fur.
Fur may appear slightly thinner over the swollen abdomen, allowing the underlying skin to be more visible. Some females develop a subtle sheen on the coat due to hormonal changes, while others retain the usual texture.
Weight increases steadily, often doubling the pre‑pregnancy mass. A pregnant rat may weigh 250–350 g, compared with 150–200 g for an adult female of the same strain.
The tail remains proportionally unchanged, but the skin over the tail base may stretch slightly to accommodate the growing uterus.
Behavioral cues accompany the physical signs: reduced activity, nesting behavior, and a preference for secluded, warm areas. These observations, combined with the anatomical indicators, provide a reliable assessment of gestational status in domestic rats.