The National Zoo has done a great job at utilizing their scientists to help introduce students to the scientific process. One of the big complaints about K-12 science is that the students very rarely "do science". Students learn about scientific topics and content but they rarely behave in the way scientists behave on a daily basis. Squirrelly Behavior is a great example of "doing science" in the classroom.
By using squirrels as the subject almost any student in the country (or world) can recreate the experiment. Scientists from the National Zoo introduce the topic and the experiment and, the site a step by step lesson plan, worksheets already created and, a data entry page which outputs a pie chart identical to the one the scientist uses in her presentation.
For late elementary or middle school students this lesson gives students a real world example of animal field work. They will work in pairs or small groups, observing animals, recording data, analyzing and displaying data and drawing conclusions. This is a great lesson to introduce the scientific process, field work or group work into a classroom.
There is one plug in necessary for the video so make sure the computer you are going to show the 10 minutes video on has the correct plug in installed.