26 
BULLETIN 1151, U. S. DEPARTMENT OF AGRICULTURE. 
The outside base measurements are 3 feet 6 inches long by 2 feet 10 
inches wide, the front side 2 feet 7 inches high and the rear 2 feet 
1 inch. 
UNDERGROUND DENS. 
The underground den is a recent type. Advantages claimed for 
it are that it deadens sound and preserves an even temperature all 
the year round, thus protecting the foxes 
from extremes of heat or cold ; it is an excep- 
tionally cool place on hot days in summer. 
This den will prove satisfactory onty in 
"ig. 26. — Vortical cross sec- 
tion of barrel den. 
Fig. 27. 
Horizontal longitudinal section 
of barrel den. 
light, well drained, chiefly sandy, soils ; it is not practicable in heavy 
soils or in those containing outcroppings of rock which make exca- 
vation very difficult. Figure 31 gives plan of construction. 
Underground dens are made chiefly of wood, but a few ranchers 
have used hollow building blocks and cement. It has yet to be 
determined whether the last-mentioned materials make the foxes 
Fig. 28. 
-Vertical longitudinal section of 
barrel den. 
Fig. 29. — Exterior view of barrel den. 
more comfortable. The main parts are assembled before being 
placed in the hole excavated for the purpose. The den proper is 
generally placed in an alleyway between the pens, while the chute 
runs from the den into the pen yard. Inspection is made through 
the manhole at the top without going into the fox pen. Figure 32 
shows the arrangement of dens in the alleyway. 
