It's not every day that you see a goopy putty appear to devour objects by slowly rolling over their surfaces. It can appear downright creepy. But when it all comes right down to it, the reason you see what you see in this video has everything to do with magnetic fields working in the background.
The goop is actually a magnetic particle-infused putty, while the objects it is devouring are actually powerful neodymium magnets. The magnetic fields of the particles in the putty are randomized, and the pulling effects of the neodymium magnets are what pull the putty over their surface area of the magnets.
The magnet tries to evenly distribute the magnetic forces across the surface area of the magnet, which is why it pulls the putty. No matter the shape of the magnet, or the size, the putty seems to always display the same results.
Using a time lapse camera, the person behind the magnetic works of art captures the process frame-by-frame, and then creates an animation out of the many frames.