For today's activity we are going to use stuff you already have at home. If you don't already have these items at home, then you know what to put on your shopping list. But I am betting most of you have this stuff. You will need: a tray (can use a pie plate too), milk (I heard whole works better with this but we were pretty happy with the results we got with 2 %), food coloring, tooth picks, dish soap, and small cups (are you saving those applesauce cups yet? They would be perfect for this).
Pour some milk in the tray. You'll want to make sure the tray is fully covered with milk so you can no longer see the bottom. Then have your kids help you squeeze drops of food coloring into the milk.
Squeeze some dish soap into your small cup. You do not need a lot, only enough to dip in a toothpick. Give your child their toothpick and have them dip it in the soap and then dip it into the food coloring and milk. My girls were delighted with this step as the food coloring started moving in all different directions. B squealed with delight as the milk moved. "Look it's dancing!" I didn't have the heart to tell her that it was not really dancing but that the soap had disturbed the surface tension of the milk which caused it to spread apart when the toothpick touched it. I'm kind of a buzz kill that way, but I held back this time.
I admit, even I was impressed by this effect. So impressed, I took A's toothpick and tried it myself. It was so fun! A was not pleased with this, so I stopped playing and gave her back her toothpick. Note to self - must do this when the girls go to sleep.
A really neat thing about this was that even when the girls were not touching the milk with the toothpick, it would keep on moving the colors around. So it was fun to just sit and watch. I could not really capture this with my camera so you will just have to try this yourself.
When she was done with her toothpick and soap, "A" discovered that she could also mix the colors by blowing on the milk. Her twin of course was quick to copy and soon I had two girls huffing and puffing.
What I really liked about this activity, was that it can be used with small kids like mine or older kids where you can bring in more of the science behind the magic. I think that as I do this again when the girls are older, they will get something totally different out of it. For now it made a great preschool experiment.