While common in the classroom, most forms of lice are not welcomed guests. Sewer lice, however, is an exception making its way into classrooms across the country. The reason is that sewer lice is not really lice. It is a popular classroom activity that helps children learn the basic principles of scientific observation.

Preparation For the Sewer Lice Activity

Cola or sewer water?
Cola or sewer water?

Use a clear glass or plastic container to hold "sewer water." You need enough cola to fill the container, a small box of raisins and a small "critter keeper." The "critter keeper" can be made out of anything that looks suitable for housing live insects.

Just before the lesson begins, fill the clear container with cola. Remove the raisins from the box and place them in the critter keeper.

The Sewer Lice Story

Tell students that sewer lice live in sewers around the world.
Tell students that sewer lice live in sewers around the world.

Show the students the container which was previously filled with soda. Tell them that this brown liquid is water collected from the sewer. Explain that they are going to learn about amazing creatures called "sewer lice." These creatures dwell in sewers around the world. Their main source of food is raw sewage. Tell the students that sewer lice are being used to help purify sewer water by digesting the sewage. They leave the water clean enough for drinking.

Introducing the Sewer Lice

A carry out box can be used to house the sewer lice.
A carry out box can be used to house the sewer lice.

Open the "critter keeper" and drop in 10 to 12 raisins. The raisins will appear to move around in the water due to the carbonation. Talk with the students about what they see. Comment on different parts of "sewer lice" anatomy, such as legs, head and mouth.

Explain to the students that sewer lice have been found to be rich in vitamins and minerals. They are being raised as a food source in other countries. Demonstrate by eating a raisin. Test the "sewer water" to see if it is drinkable. Ask if anyone would like to try it with you.

What Students Learn

Students should learn to evaluate their own observations carefully by using the Scientific Method.
Students should learn to evaluate their own observations carefully by using the Scientific Method.

After you have revealed the secret of the sewer lice, ask the students what they have learned. This is a good time to introduce the Scientific Method of Observation. Discuss the importance of careful study and evaluation in the scientific world.