Aged Rodent Colonies Handbook

The chart below provides the age at which 90%, 75%, 50%, 25% and 10% of the population has survived. These ages are averages derived from large populations (from Turturro et al., 1999), so survival data in small groups of animals will vary. Please Note: the NIA typically will not ship animals past the 25% survival age, as very old rats and mice are frail and more sensitive to the stresses of shipping. Very old rats and mice are also more prone to underlying age-associated diseases and are not a good research model for most purposes.