1971] 
Talbot — Formica dakotensis 
171 
dug-out soil was noticed just in front of it and workers were begin- 
ning to carry other workers from various mounds to this one. When 
leaves were cleared away a labyrinth of pathways was found cut 
into the soil and going into the mound’s base. Each day hereafter, 
until observations ceased on October 1, ants were seen carrying 
other ants into the lower part of the mound. Evidently this was 
the hibernating place for the whole colony. On June 3, 1971 workers 
were carrying other workers out from this mound. 
Trails and foraging grounds. Among the grasses of the nest area 
there was a superficial trashy layer of loose tree leaves, stems, etc., 
and under this the usual matted layer of compressed leaves decaying 
into the soil. It was this soil-leaf stratum which the ants used for 
tunneling to their foraging grounds. Their food seemed to be aphid 
honey dew but very little attending of above-ground aphids was 
seen. In 1970 the only workers seen foraging above-ground went by 
tunnel for about 10 feet and then up into a small poplar tree. Here 
5 to 15 ants at a time attended aphids on leaf petioles. 
Most of the hidden aphids were on bases of spirea stems. Only 
the young, green stems were used and all such stems investigated had 
the lowest inch or two covered with aphids. If the lower stem had 
leaves piled aboout it, no structure was built but if the aphids 
extended above the leaf layer, a very tight thatch shelter encircled 
them. These thatch collars were rather easy to see and were very 
abundant but no ants were seen upon them because runway tunnels 
took the ants directly into their bases. Perhaps the ants also attended 
root aphids. There were some tunnels extending into the soil be- 
neath the plants but no aphids were found on roots. In the grassy 
area in front of the nest ants were seen going into several holes at 
sides of clumps of grasses. One such clump was dug and aphids were 
found at the base of leaves, where stem and roots joined. 
The other two colonies were more typically field ants, being further 
away from shrubs and trees and more directly dependent on field 
plants to harbor their aphids. The larger colony, near Southwest 
swamp, had 8 major mounds spread over 19 feet. It lay in a field 
of Poa compressa grass, goldenrod ( Solidago nemoralis Ait.), iron- 
weed ( Verononia altissima Nutt), Queen Anne’s Lace ( Daucus 
carota L.) and small scattered dogwood (Cornus stolonifera Michx.). 
Runways radiated from the mounds to many of these plants which 
had small thatch shelters surrounding their bases. All of the aphids 
found were just below ground level where roots and stems met. 
The smaller colony, on a grassy slope above a cattail marsh, had 
only three main mounds spread over 27 feet. It had a number of 
