How does a rat care for its offspring? - briefly
A mother rat constructs a nest of shredded paper or cloth, then nurses the newborns and maintains their temperature by huddling and grooming. She also cleans the litter, stimulates elimination, and gradually weans the pups by decreasing nursing and encouraging independent foraging.
How does a rat care for its offspring? - in detail
Rats begin parental investment the moment fertilization occurs. The gestation period lasts approximately 21–23 days, after which the dam gives birth to a litter of 6–12 pups. Immediately following delivery, she creates a nest of shredded material—paper, cloth, or bedding—to provide insulation and a secure environment. The nest is positioned in a quiet corner of the cage, away from food and water sources, to reduce disturbance.
The mother performs several critical functions during the early post‑natal phase:
- Thermoregulation: She curls around the pups, generating heat through her body temperature. If ambient temperature falls below 30 °C, she increases huddling frequency to maintain pup body temperature within the optimal 34–36 °C range.
- Feeding: Mammary glands produce milk rich in protein, fat, and antibodies. The dam nurses the young every 1–2 hours, with each session lasting 2–5 minutes. Milk composition changes as pups mature, providing higher fat content during the weaning period.
- Grooming: She licks each pup, stimulating urination and defecation, and removing debris that could attract pathogens. Grooming also reinforces the olfactory imprint that identifies the litter as her own.
- Protection: The dam exhibits heightened aggression toward intruders, including other adult rats, to safeguard the nest. She emits ultrasonic vocalizations that signal distress to conspecifics, deterring potential threats.
Around day 10, pups begin to develop thermoregulatory independence. The dam gradually reduces nursing frequency, encouraging the young to explore the environment and practice locomotion. By day 14, solid food is introduced; the mother places small pieces of softened chow near the nest, allowing pups to sample it while still receiving occasional milk feeds.
Weaning is typically completed by day 21. At this stage, the mother ceases lactation and redirects her attention to self‑maintenance. She continues to provide occasional social contact, which supports the development of social hierarchies and coping mechanisms for future breeding cycles.
Throughout the reproductive cycle, hormonal fluctuations—primarily prolactin, oxytocin, and estrogen—modulate maternal behaviors. Elevated prolactin levels sustain milk production, while oxytocin facilitates bonding and nest‑building activities. After weaning, a decline in these hormones coincides with a reduction in maternal responsiveness, preparing the dam for subsequent estrous cycles.