Scientific Tuesdays - How to make Magnetic Fluid (ferro fluid) --this would be fun to put in a sealed discovery bottle and let children watch what happens when they apply a magnet
You can make your own ferrofluid (a liquid that becomes strongly magnetized in the presence of a magnetic field) for experiments
Make ferrous fluid
Ferrofluid climbs up objects that have exposed details and ridges.
DIY ferrofluid a tutorial on how to make magnetic lava tubes-Magic
How to Make Ferrofluid: The Liquid of the Future « Fear Of Lightning
Learn how to make your own ferrofluid