This lab is fabulous! It has just the right amount of "gross" to hook any age student. I completed this lab during the 2nd week of school as part of my science inquiry unit. In this lab, students complete tests on real-life leeches to observe behaviors and make inferences about why they behave that way. This lab will also work well when studying animal adaptations. I purchased 1 lb. of ribbon leeches from an online bait store for about $40. It was a little expensive,but well worth it from the student engagement. 1 lb. of leeches was more than enough for my 130 8th grade students. I used 1/2 lb. deli bowls with lids for the tests. These can be purchased at Sam's club or donated by grocery stores.
Students complete the following tests on the leeches:
1. Observe color, shape, and swimming motions
2. Find mass and length
3. Reaction to vibrations by tapping on bowl with ruler
4. Reaction to moving water by swirling water in bowl with finger.
5. Reaction to light and dark with a flashlight and index card.
6. Reaction to scent by dropping vinegar in lid with leech.
-You must be careful with the vinegar test. Vinegar dropped directly on the leech will kill it. Do this test on the bowl lid with a small amount of water so you don't contaminate the entire bowl.
The ribbon leeches cannot harm you or the students. They are much like worm, but the students find is very cool that the leeches will stick to them with their suckers.
If you decide to complete this lab, I will be happy to help in any way I can.
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