Joe has finished his experimentation to time how long it takes mice to complete different mazes in the laboratory. He used three mice for all of the different trials he performed. All of them were allowed to complete mazes A, B, and C during his experiment. Why did Joe use the same three mice for his testing? Using the same mice made them the independent variables because he had each of them run all the different mazes. Using the same mice made them the dependent variables because their time depended on the food they were given. Using the same mice was a constant in his experiment because if he had used random mice, he might have had trouble telling why one was faster. Using the same mice made them a control group because they didn't have any variables applied to them.