1986] Herbers Tucker — Leptothorax longispinosus 219 
The artificial forest floors were lm X lm in size. Each had a red 
glass base upon which autoclaved pine needles, leaf fragments and 
other debris typical of the habitat were scattered. The sides of the 
floor were coated with petroleum jelly to prevent worker escapes, 
and the entire structure was enclosed in mosquito netting to restrict 
alate fights. Lights above and below the red glass base provided 
illumination. The temperature was maintained at 18-20°C and rela- 
tive humidity at 60-90%. Periodically water was sprinkled on the 
floor to simulate rainfall. In addition to placing nests on the floor 
according to where they had been collected, we supplied additional 
tubes so that each floor had a total of 10 nesting sites. Nests were 
supplied with water ad libidum and solid food (both frozen fruitflies 
and a formula based on Bhatkar and Whitcomb’s (1970) recipe) 
three times weekly. Detailed observations of behavior were taken 
for the first 3 weeks (2 hours of continuous observation daily from 
9:00-11:00 as well as periodic checks), after which the intensity of 
observation was reduced to 2 hours per week. Nests were censused 
daily for the first two weeks and weekly for the rest of the period. 
Results 
The initial contents of nests are given in Table 1. Four nests on 1 A 
(all polygynous), three nests on IB (one queenless, one monogy- 
nous, one polygynous) and five nests on 2B (two queenless, one 
monogynous, two polygynous) were positioned to duplicate their 
natural locations with respect to each another (Figure 1). 
Direct observations of the ants showed that initially aggression 
was common: workers engaged in fighting behavior, wherein two 
workers would interlock mandibles, attempt to sting each other, 
push or pull by the mouthparts, and so on. These encounters some- 
times resulted in death of one or both participants. Not all interac- 
tions were aggressive, however; workers were observed to carry 
other workers, brood, and in one case a queen outside the nest. 
Several occasions of tandem running (which usually precedes a col- 
ony migration (Moglich 1978) were observed. In addition to inter- 
acting with other ants, workers were often observed to explore, 
forage, and manipulate pieces of detritus and food. 
Particularly striking was exploration of the empty tubes which 
represented potential new nesting sites. This exploratory behavior is 
