Southwestern Middle School science teacher Don White, top, stops a rat from climbing up his arm while talking to his students about lab rats which will be used to study the affects of nutrition on the animals. The two rats will be fed an identical diet of solid foods, but one will be given milk to drink while the other is given sugar water. The sugar water has the same number of calories, but none of the nutrients found in milk. The students will learn nutritional information and the importance of maintaining single variables in scientific experiments. Bottom, sixth-grader Tucker Ciulla looks on as classmate Kenzie Roark holds one of the rats. (Staff photos by Ken Ritchie/kritchie@madisoncourier.com)