Hooked on Science: Sewer lice

Get an audience together and learn how some sewage plants use sewer lice to clean sewage water.

Materials

* Raisins

* Transparent container

* Mountain Dew

Instructions

STEP 1: Inform those in the audience you stopped by the local sewer plant for a sample of sewer lice to observe how they clean sewage water.

STEP 2: Fill the transparent container halfway with "sewer water" (Mountain Dew).

STEP 3: Drop several "sewer lice" (raisins) into the sewer water and observe.

Explanation

Your audience will eventually realize what's floating inside the Mountain Dew is not sewer lice. Inform them that once enough carbon dioxide bubbles in the Mountain Dew collect on the sides of the raisins they "swim" to the surface. Once at the top, the carbon dioxide bubbles pop and the raisins "swim" back to the bottom. Inform your audience that sewage is cleaned at a sewage plant through one, two or three stages and not sewer lice.

Jason Lindsey is a science outreach educator with Hooked on Science. Check out his website www.hookedonscience.org for webcasts and experiments that might get you hooked on science.