We are having Mad science week at day care this week for March break and this is something we did during Halloween and I am doing it again this week. I saw it all over pinterest in the fall so I can't take credit for it but I thought I would share it with you incase you haven't tried it yet!
All you need a some vinegar and food coloring. A few droppers. I bought mine a the school supply store because we use them all the time but before we used these I was saving the ones from the Tylenol bottle and asking for extras at the pharmacy. shhhh don't tell them that's what we were using them for.
Then you just ad some baking soda to a tupper ware container and let them drop away.