Quicksand

Some believe that the main reason is that the sand here have the correct spherical form. Therefore, any heavy objects immersed in them very easily. Another assumption is that grains are sometimes slippery. Conducted such an experiment. On the dry sand was placed human figures made of plastic and weight equal to the mass of the human body. Then sand heavily moistened. If it is watered from above, then plastic mannequins remained on the surface. But as soon as the water pumping in sand from the bottom, like mannequins quickly sank in the sand. Incidentally, the common marsh morass is still referred to zybunom. Gak that quicksand, judging from this experiment is likely a close relative of the quagmire, zybunu.