One advantage to using model mice is that they would stay in one place, making observation of predator attacks easier for the scientists. One disadvantage is that the models will never act like real mice, which could affect whether predators would want to attack the models.
Work Step by Step
To come up with a good answer, consider the habitat (hot, dry, sunny, sandy, salty dunes in Florida). Think about why this is better/easier for the experimenter. There are other possibilities than the one answer given. Then, think about how using non-living, non-moving mice is not "real." Again, there are several possible correct answers.