Objective: The students will learn to use their sense of smell to become more aware of how certain animals hunt their prey.
Grade level: Elementary
Time: 20 minutes; fall or spring
Materials: 2-6 fresh onions, pieces of brown yarn or string
The sense of smell is an important "tool" to investigate the environment. It is especially crucial for certain animals like foxes, which often track their prey by following scent trails. In this activity the students will try to follow a scent trail by using their sense of smell.
Activity Description: Explain to the students that they will be using their sense of smell to follow a trail, just as many other kinds of animals (such as clogs and foxes) do. Divide the class into 4 teams and assign each team in an area in which to layout it scent trail. Give each team a piece of string or yarn and a fresh onion which has been sliced in half The teams then have a given amount of time (3-5 minutes) to layout a scent trail in their mea by rubbing the onion across tree trunks, telephone poles, rocks, walls or other places (the marked objects should not be much further than 5- 10 feet apart). After marking about 10 objects the team should tie the piece of yarn on the last object on their trail to mark its end.
When the trails have been established join the teams together and assign trails for the teams to follow (for example. teams 1 and 2 could follow each other's trails while teams .) and 4 do the same), The teams then have 5-10 minutes to try to find the scent trails by "following their noses." When the time is up, have the teams check with one another to see how successful they were at finding the marked objects along the trail. Have the students share their experiences with the class. Was it hard to follow the scent? What effect might the wind speed or direction have on this activity? Could they find and follow the same scent trails tomorrow? Is it easier to follow a fresh or an old scent trail?
Variations: You might have the teams mark only a specific number of places with the onion as they layout the trail. This way you can check to see how accurate the other teams are at following the trail. You can also experiment with other strongly-scented substances instead of onions like Old Time Woodsman Fly Dope, essence of wintergreen, etc.