34 SEVENTEENTH Report STATE ENTOMOLOGIST OF MINNESOTA—1918 
The height at which the nests are built varies greatly but they are 
usually located within six feet of the ground. They may, however, 
be occasionally built high in the trunk. As a rule, the ants gain en- 
trance to a tree at a point near the base, sometimes even below the 
ground level, starting either in the trunk or in a large root. Occa- 
sionally entrance may be gained through a knot-hole in the trunk. 
This latter is usually the case when the nest is located at a considerable 
distance above the ground. 
Fig. 6. Window opening to the outside. 
EXTENT OF INFESTATION 
The percentage of ant infested cedars varies with the conditions 
under which the trees are growing. Trees growing in the swamps are 
much less heavily infested than trees growing on higher ground. 
Counts made on plots laid out under various conditions showed this 
to hold true in every locality studied. A very good example of this 
difference was shown in a series of plots located near Blackduck, Min- 
