Sewer Lice!

I have known of Flinn’s “Sewer Lice” activity for several years, but I have never tried it.  I thought it would be a cute demonstration to use on the day I discuss characteristics of living organisms.

If you’ve never seen the write-up before, it basically involves putting some sort of carbonated beverage in a beaker and then adding a handful of raisins to it.  The raisins are supposed to move around in the liquid as a result of the the CO2 bubbles.

Golden Raisins

I recalled reading online once upon a time that someone suggested using golden raisins, as they are typically less recognizable to students than the usual dark variety.  So I bought some Sprite, Dr. Pepper, and golden raisins at Walmart to test this out.

To my disappointment, the raisins fizzed A LOT when I dumped them in the 600 mL beakers (I had one beaker full of Sprite, one with Dr. Pepper, and the other with a 50/50 mix of the two), but they didn’t move much.  Needless to say, I didn’t bother showing the students or use them as discussion (though I guess it could’ve been a good discussion of how sometimes we don’t get the results we expect, yada yada). 

Has anyone else attempted this activity?  How did it work for you, and what did you use?  Thanks!