Abstract
Rat offspring malformed as a result of maternal exposure to a teratogen were cannibalized preferentially to apparently normal offspring. Lack of viability also appeared to be a factor in the cannibalistic tendency, since both normal and malformed dead pups were consumed more frequently than viable pups of either category. Of the 29 cannibalized pups observed, 86% were cannibalized in the 1st 24 h. The cause of this behavior is not known with certainty but maternal hormone imbalance may play an important role.