This booklet is part of a series which tests some skills biologists use in their investigations. Questions are asked about investigations of the maternal behavior of rats, which is related to the "puzzling events" presented in a series of photographs of rats in Skinner boxes in Booklet A (SE 011 340). In a series of questions, depending upon the student's choice of experiment, data interpretation skills are tested. No time limit is indicated for this booklet. (AL)