• Mice: Female mice typically become sexually mature around 6-8 weeks of age, while males may reach maturity slightly later, around 8-10 weeks. They can start mating as soon as they reach this stage of maturity.
• Rats: Female rats usually become sexually mature around 5-6 weeks of age, while males reach maturity around 6-8 weeks. Like mice, they are capable of mating once they reach this level of maturity.
• Physical Development: By 2-3 months, the animals are fully developed physically, which can lead to healthier pregnancies and litters.
• Behavioral Maturity: Older animals are typically more stable and less likely to exhibit stress-related behaviors that can affect breeding and offspring.
• Health Considerations: Younger animals might still be undergoing growth and development, which can sometimes lead to complications in pregnancy and birth. Waiting until they are a bit older helps ensure that they are in better overall health.
• Reduced Risk: Breeding at a slightly older age can reduce the risk of health issues for both the breeding pair and the offspring.
• Randy Bilesky BScF CPA RPF
• President at Go Green
• August 26, 2024

It’s worth noting that for optimal health , breeding often happens when the animals are a bit older than the minimum maturity age, typically around 2-3 months old.

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