Prairie dogs live in large colonies in complex interconnected burrow systems. They face the problem of maintaining a sufficient air supply to their burrows to avoid suffocation. They avoid this by building conical earth mounds about some of their many burrow openings. In terms of Bernoulli's equation, how does this air conditioning scheme work? Note that because of viscous forces the wind speed over the prairie is less at closeto ground level than it is even a few inches higher up. (See New Scientist, January 27, 1972, p. 191.)

Prairie dogs build conical earth mounds in some of their burrow openings.
The schematic diagram of such burrow system of the Prairie dogs is shown below:

From Bernoulli’s equation, the total energy of the flow of air at the point 1 and 2 remains the same. Also, the increase in pressure is accompanied by the decrease in the speed of the air and vice versa. It is also given that the speed of air over the prairie is less as close to ground level. From the figure, the speed of the flow of air is lower at the point 1 than at point 2. From Bernoulli’s equation, the pressure at the point 2 is lower than at the point 1. Thus, air will rush from higher pressure 1 to the lower pressure 2. This means air will flow from outside to inside of the burrow. Therefore, a natural air conditioning in the burrow system works due to the inflow of the air inside the burrow.