“Sewer Lice” (pdf) is a Flinn Scientific, Inc. demonstration for “What Is Life?” to introduce some levity into the classroom and to provide an opportunity to discuss the importance of careful observations. One teacher from the NSTA ListServe suggested using white or golden raisins to make them harder for students to recognize.
“The Scientific Method” activity has students write a paper about the scientific method and then use it to solve a problem. Rubrics are included.
A good middle school activity for introducing controls and variables in an experiment is “Identify the Controls and Variables” with the Simpsons. Lisa Smith from the NSTA Listserve has used the site to create the worksheet “The Simpsons – Identifying the Controls and Variables” (word doc).
Labs
Introduce The Scientific Method by hatching “dinosaur eggs” with this (word doc) experiment.
Or introduce The Scientific Method with this “Testing a Consumer Product” (word doc) lab.
Explore the characteristics of life with “Is Yeast Alive?” Lab (word doc) or (pdf) with these teacher notes (pdf).
Use the scientific method to “Save Fred” (word doc). And here is another “Save Fred” (word doc) worksheet with good images, but has to be printed on office size paper.
“The Checks Lab” is a nature of science activity from ENSI.