How should a pregnant mouse behave? - briefly
A gestating mouse reduces aggression, selects secluded nesting locations, and limits movement to conserve energy for fetal development. It increases consumption of protein‑rich food and intensifies nest‑building activity.
How should a pregnant mouse behave? - in detail
A gestating mouse exhibits specific physiological and behavioral adaptations that support fetal development and ensure survival of the litter.
Nutritional intake rises markedly. Food consumption may increase by 30‑50 % compared with non‑pregnant levels. Preference shifts toward high‑energy and protein‑rich foods, such as seeds, nuts, and commercial rodent chow formulated with elevated caloric density. Water consumption also escalates to maintain hydration and support amniotic fluid production.
Activity patterns change. During early gestation, locomotor activity remains comparable to baseline, but as gestation progresses, the mouse reduces exploratory behavior and spends more time in the nest. Nesting material is gathered intensively to construct a secure, insulated environment for parturition. The nest is typically compact, with thick layers of shredded paper, cotton, or soft bedding.
Social interactions become more selective. Aggressive encounters with conspecifics decrease, and the mouse avoids unnecessary confrontations that could jeopardize pregnancy. If housed with other females, a clear hierarchy may emerge, with the pregnant individual receiving priority access to resources.
Thermoregulation intensifies. Core body temperature may rise slightly, prompting the mouse to seek warmer microhabitats within the cage. Providing a localized heat source, such as a heating pad set to low temperature, supports thermoregulatory needs without causing hyperthermia.
Reproductive physiology manifests through observable signs:
- Swelling of the abdomen becomes evident around day 10‑12 of gestation.
- The nipples enlarge and become more pigmented, indicating mammary gland development.
- Vaginal discharge may appear, consisting of clear or slightly milky fluid.
Stress susceptibility increases. Exposure to loud noises, sudden movements, or abrupt environmental changes can trigger corticosterone release, potentially affecting fetal growth. Minimizing disturbances and maintaining a stable environment are essential.
Monitoring guidelines:
- Record daily food and water intake to detect deviations from expected increase.
- Observe nest construction; inadequate nesting may signal discomfort or health issues.
- Check for signs of dystocia or prolonged labor as parturition approaches (typically around day 19‑21).
- Conduct periodic weight measurements; a steady weight gain of 2‑3 g per day is typical for a healthy pregnancy.
Providing a balanced diet, ample nesting material, a quiet habitat, and regular health assessments ensures optimal behavior and outcomes for a mouse undergoing gestation.