1980] 
Stuart & Bell — Leptothorax 
205 
C. Feeding 
L. muscorum workers stridulate intermittently as they bite, pull 
and tear apart solid food such as insect fragments, both outside and 
inside their nests. Stridulation is seen among groups of workers 
biting on a common food item, and is also displayed by workers 
biting on tissue individually. In culture, workers do not normally 
stridulate when consuming liquids. However, if a colony has been 
deprived of food and water for 5-7 days, workers will frequently 
stridulate when consuming honey, Bhatkar and Whitcomb diet, or 
even water. 
D. Trophallaxis 
When foragers return to the nest after having consumed liquid 
food, they engage in oral trophallaxis with adult members of their 
colony. Recipients hold their mandibles closed during trophallaxis 
and frequently stridulate; while donors hold their mandibles open 
and occasionally stridulate. In one study, 20 bouts of trophallaxis, 
lasting longer than 10 sec, were observed in each of three colonies. 
Thirty-eight bouts had a single recipient, eleven had two, seven had 
three, three had four, and one had five. Forty-seven of the 98 
recipients stridulated at least briefly during trophallaxis; while only 
4 donors did so. At least one recipient stridulated in each of 38 
bouts, and both donor and at least one recipient stridulated during 
two bouts. Stridulation occurred in short bursts and prolonged 
sequences, and appeared to occur more often near the end of bouts, 
or when additional workers joined groups already engaged in 
trophallaxis. 
L. muscorum workers also stridulate during certain bouts of oral 
trophallaxis with larvae. During the feeding session described 
above, five incidents of trophallaxis between workers and larvae 
were recorded. They lasted 5, 6, 10, 20, and 25 sec respectively. In 
each case the worker stridulated for nearly the entire bout. How¬ 
ever, on other occasions workers have been observed engaging in 
apparently similar bouts of trophallaxis, but with no stridulation 
whatsoever. In either case, it is unknown whether the workers 
involved were actually giving liquids to the larvae, or receiving 
them. 
E. Allogrooming 
In laboratory colonies, L. muscorum workers often lick the body 
surfaces of their nest-mates. This grooming is directed to adults and 
