I am so impressed with myself! LOL I applied some of my chemistry knowledge to a real life situation. The twins had an aquarium mobile in their room that stopped working about 5 months ago. I had put it in a box and was going to throw it away, but it got left in the garage. I found it the other day and tried to make it work, but nope, it didn't work. So, Chris threw it away. Yesterday in Chemistry I learned that if the prongs where you put batteries are corroded, you just have to use some sandpaper to get the corrosion off the object will work again. Well, guess what? It did work!!! I was going to go spend $30.oo on a new one, but I just got this one to work again with a little sandpaper. :) Oh, and if the prong is broken, you can just fold up some aluminum foil and use that as a conductor! Isn't that sooooo cool??? :)