There is, but not like in the old Tarzan movies. This type of terrain can even trap an animal, but seeing a person being swallowed, only in the cinema. In addition to being difficult to find a very deep quagmire, the person who sticks his feet in it will still have his arms free, just need to lean on nearby areas with firmer soil to get out. The main victims are animals, which get stuck with all four legs and have no way to escape. Even so, the danger is not the animal being swallowed, but dying of hunger if not rescued.
1. An area with normal sand has tightly packed grains, very close to each other. It’s like the sand is pressed. On a beach, for example, the action of the wind and the people and objects that circulate on top of the sand help to stick the grains together, making the ground firmer.
2. Under certain conditions, sand may become less compacted. In a region between dunes, for example, the grains brought by the wind are protected from air circulation and end up remaining looser, forming soft sand. This is a type of place that can give rise to quicksand
3. If this soft sand receives a lot of water, like rain, the grains that were already a little loose separate even more. The vacant spaces are filled by water, creating a viscous mixture of sand and liquids that is the popular quicksand, called fluidized sand by geologists.
4. If an animal steps into this unstable area, the grains of sand begin to move towards the bottom, carrying the animal’s paws together, as if they were “giant grains”. By the time his paws reach a level of more compacted sand, he may be completely bogged down.