How long does it take for rats to mature? - briefly
Rats become sexually mature at roughly five to six weeks of age for females and six to eight weeks for males. This period marks the onset of reproductive capability.
How long does it take for rats to mature? - in detail
Rats reach developmental milestones rapidly compared with larger mammals. After a gestation of approximately 21–23 days, newborn pups are born altricial, blind and hairless. They open their eyes around day 13–15 and develop fur by day 18.
Weaning occurs between day 21 and day 28, when the young can sustain themselves on solid food. Sexual competence follows shortly thereafter:
- Females attain estrus and can conceive at 5–6 weeks of age (35–42 days).
- Males become capable of successful mating at 6–8 weeks (42–56 days).
Physical maturity, defined as reaching full adult body mass and skeletal growth, is typically observed at 10–12 weeks. At this stage, a Norway rat (Rattus norvegicus) weighs 300–350 g, while a domestic fancy rat may be slightly lighter.
Factors influencing the timeline include:
- Strain: laboratory strains mature slightly earlier than wild‑caught counterparts.
- Nutrition: high‑quality, protein‑rich diets accelerate growth; caloric restriction delays it.
- Ambient temperature: optimal housing (20–26 °C) supports normal development; colder environments prolong maturation.
In summary, a rat progresses from birth to full adult status within roughly three months, with reproductive capability emerging after five to eight weeks. Adjustments to genetics, diet, and environment can shift these intervals by a few days to a couple of weeks.