Lesson Summary In this lesson, students will observe the crayfish’s behavior when it is presented with different situations.  Each group will put their crayfish into its feeding basin and use Student Sheet 14 to guide the activity.  When all groups are finished, the groups will share the different behaviors they saw from their crayfish, and why they might have seen a particular behavior.  This lessons ends with a brief assessment using Student Sheet 15 to determine if students understand the concept of structures of an organism.  Teacher Background This lesson gives the students an opportunity to act like a real scientist, because they must record all their findings as they happen.  Remind the students that they need to record exactly what they see, and provide them with an example, and explain why this is an important skill. Set-up/Management Tips Continue to refill your water to be aged overnight. This lesson can be done over two days, since students like to create their own scenarios for the crayfish, often involving multiple crayfish at a time, just remind the students how to keep the crayfish safe. Literacy Support Scientific Vocabulary The following words are key vocabulary words that will be introduced in this lesson and reinforced throughout the unit: behavior