Entomology and Zoology Department. [Bull. 168 



certain direction. Approaching from another quarter of the 

 infested plat the surface runway will again be found to turn 

 downward somewhere in the same direction as before. These 

 deeper runs are the highways leading from the mole's home to 

 his hunting grounds. In fact, they may be said to constitute a 

 part of his permanent residence, although the home proper is 

 an irregular chamber here and there connected with these 

 runs. The latter follow a course from five to seven or eight 

 inches beneath the surface of the ground deeper than the soil 

 is usually stirred by agricultural operations. The chambers 

 from which these runs radiate are not large, their average ca- 

 pacity being about a quart. These investigations have never 

 revealed any nesting material in them. The American genera 

 of moles do not construct "mole hills," as the European genus 

 Talpa is said to do. 



Clean ground 



Tall stubble and weeds 



f 



VeryshorT sTubble 



Medium s tubble and weeds 



Plot of ground in which a mole runway was excavated. The total length of the parts 

 of the runway shown was 475 feet. The deeper parts of the runway are just to the left 

 of the center of the illustration. Several small chambers were found in this part of the 

 system. 



By far the greater extent of a mole's system of runways is 

 made up of the shallow burrows ranging over his hunting 

 grounds. , These are merely subsurface paths pushed hither and 

 thither by the vigorous little animal in his search for food. 

 They may not be used again or they may be retraversed at 

 irregular intervals. After a time they become filled up by the 

 settling of the soil above, especially after heavy showers. In 

 some cases, also, the mole evidently pushes into them the dirt 

 which he has excavated in his deeper runways. These sub- 

 terannean hunting paths are about an inch and a quarter to an 



