Unlike other forms of matter, Ferrofluid is both a solid and a liquid. And since it is made of metal, it can hold a variety of unusual shapes. Color-wise, it is usually black, though you can add dyes to change its hue. Either way, a very small amount of the substance is needed for a typical science experiment.
In any case, once you have made a Ferrofluid purchase, place the substance on some glass. If you are somewhat handy, you can make a glass platform. Otherwise, you will have to use an older window. With a window, the frame will keep you from getting cut. Just make sure the window is suspended in mid-air, (as it cannot be attached to your house). The fluid will move around on the glass surface.
Now take a magnet and place it under the glass pane(s). The particles in the Ferrofluid will acquire a magnetic charge, causing them to move and form odd shapes. In fact, the liquid will actually rise and take solid form. No matter how you move the magnet, or even the window, the substance will begin creating different sets of patterns. In other words, the Ferrofluid will develop a mind of its own. Just make sure you do not remove the magnet, as doing so will cause the design to collapse. When this happens, you will have to start over from the beginning, as Ferrofluid needs magnetic energy to fuel its movement.
You now have a basic understanding of how Ferrofluid works. The next step involves making a Ferrofluid purchase. You can acquire the substance pretty easily through auction sites or specialty stores. However, if you are new to this type of compound, you may want to look at Ferrofluid pictures to see how it works. These images will also give you ideas for experiments, if you want to expand on what has been explained here. If you and your child are exceptional with Ferrofluid, you can even make art with your creations. Who knows… the “simple” experiment your child does today could end up in a museum tomorrow. That is how powerful Ferrofluid can be, when applied in an artistic manner.