The swamp can occur for two reasons: the growth of pond or water logging of land. The swamp is characterized by excessive humidity, a constant deposition not before the end of decomposed organic matter called peat. The ability ingestion of objects have not all swamps, and those in which it formed a bog.Quagmire swamp is formed, as a rule, in place of the lake. Lilies, lilies and reeds on the lake's surface over time, grow in a dense carpet on the water surface. Meanwhile grow and algae on the lake bottom. As the cloud of algae and moss rises from the bottom to the surface. Due to the lack of oxygen starts rotting, organic waste are formed, which disperse in water, forming a bog.Quagmire has the insidious ability to suck the living objects, this is due to its physical properties. The bog belongs to the class bigamously fluids, which are physically described by the equation of the Bingham-Shvedov. The main property of these fluids is that in contact with the surface of the object has a small weight, they behave as solids, i.e. the object will not be located. But if the object has a large enough weight, it sinks.There are two kinds of immersion: nedomoganie and preporucena. The behavior of the body, trapped in the liquid, obeys the ratio of the gravity and buoyancy force of Archimedes. The body will sink into the mire as long as the force of Archimedes is equal to his weight. If the force of buoyancy is less than weight, there will be nedomoganie object on preporucena.Now, about the treachery of the quagmire that is reflected in the fact that preporuceno are only living objects (people, animals, birds). The reason is that such objects are constantly moving. It would seem that you can freeze and dip to stop, but unfortunately, it will only slow it down, because the living body is always moving because of breathing. Inanimate objects remain motionless, so completely immersed.Preporucena in a swamp and the swamp is called entrainment. Why the movement of the body speeds up the dip? Because any movement is the application of force, which increases the pressure force on the bearing due to gravity and the weight of the object. In addition, sharp movements are the cause of the formation beneath the body regions of low pressure, which will lead to an increase in atmospheric pressure in a living subject, further sinking it.Thus, the physical definition of the word "entrainment of the swamp" is as follows: bog, i.e. a Bingham liquid, trying to translate what goes in a living object on a level below normal immersion in which the Archimedes force is less than body.The process of ingestion is irreversible, i.e. the drowned body even after the end of life has been not POPs up.