Pour 3 tablespoons of vegetable oil into a smaller glass and add 1 to 2 drops each of red and blue food coloring.
Gently stir the mixture once or twice with a fork to barely break up the beads.
Pour the shorter glass into the water glass and watch.
It takes about 30 seconds for the beads to burst through the oil, releasing miniature fireworks.
This is an idea from the July/August 2007 issue of Family Fun magazine (last page).