"Animals will be socially housed (up to 3 animals of same sex and same dosing group together) in stainless steel cages equipped with a metal bar/grid type floor and an automatic watering valve unless deemed inappropriate by the Study Director. Animals will be separated during designated procedures/activities. Each cage will be clearly labeled with a color-coded cage card indicating study, group, animal and tattoo numbers, and sex. Following randomization and during the replacement period spare animals may be co-housed with the Control group. If the animals cannot been socially housed due to study activities requirements, animals will be exercised according to the Facility document." After reading the above description, please answer the following question:  will animals be social housed or single housed? The letter i should appear at least 21 times.
user