Grades K-2: Echolocation

Objective	Students will learn how sonar works and how toothed whales use it to visualize their world.
Materials	Blindfolds.
Time Frame	1/2 hour
Teacher Background	See Odontocetes in the Background Information Section
Dive In!	How do dolphins and porpoises use sound to find their way around their environment and catch food? Dolphins can find and identify different objects even when their eyes are covered. How does that work and why don't they just use their eyes?
Process	Divide students into three different sized groups. The largest group will represent fish, the mid-sized group will represent dolphins, and the smallest group will be killer whales. Have each group select a sound to make that is distinctly different from the other groups. Students should then move around the room, mixing with students from other groups. Then put on blindfolds. They must find others in their own group by making their own sound before someone in a smaller group finds them. Being blindfolded helps students imagine what it's like to see underwater and how different sounds will help them identify members of their own species.
Science Note	Fish would not actually use sonar as cetaceans do. Fish have eyes adapted to seeing underwater as well as variety of other, unique underwater adaptations for sensing their environment.
Safety Note	Students must bring in their own blindfolds.