This video is a science experiment for kids, which demonstrates how to make Invisible Ink at home. For this experiment, you will need the following: a knife, a spoon, a lemon, a cotton swab, a cup of water, paper, and a saucer. First, you will need to cut the lemon in half. Then, squeeze the lemon juice onto the saucer. Add water. Dip the cotton swab into the water to moisten it, and use it to write on a piece of paper. Write anything that you'd like. Allow it to dry. To reveal the ink, hold the paper up to a light bulb. As it heats, the writing will be revealed.