Previous

... Here's how to demonstrate it

 
In this demonstration the holes represent animal tunnels. Fill the plastic box with soil and tamp down. Then make "tunnels" by pushing through the holes. Add water from the top as needed to flood. If there are no drain holes at the bottom, the water table will rise to the lowest open tunnel; with drainholes, all tunnels stay unflooded.
Next  

205B-UCD-tunnelbox-

 

photo by Howdy Howard, published in Saved by Bedbugs (2004)
 
Home.