This is a lab for Middle School and High School Science classes. It uses Red Wigglers, Eisenia fetida, to manipulate temperature variables to affect the worm's pulse rate. Red Wigglers are easy to work with and allow students to see the blow flow through the closed circulatory system and calculate the pulse rate of the worm. This lab uses graphing and data collection to help students understand how science accumulates data to make inferences about how conditions affect animals.