1968] 
Leuthold — Crematogaster 
339 
Fig. 4. Diagram of the back-and-forth trips between food and nest. By 
maneuvering of the movable side bridge only the food finder but no new- 
comer was admitted to the side bridge. Alerting performances are repre- 
sented by black dots. 
ly with simultaneous opening of its mandibles into a parallel attitude 
(Fig. i). Both ants contact their vibrating antennae while facing 
head-on. After this short interaction the alerter retracts its head back 
to the initial position or sometimes to the opposite side. The be- 
havioral pattern is repeated up to twelve times in a stronger per- 
formance. The motions of this performance remind one of the 
movements of a dog barking at a stranger. In a few cases, however, 
the recruiter ant is also seen to perform its behavior from a higher 
position downwards to the head of its passive partner. At the end 
of a volley one or a few last strokes are directed at the flank of the 
partner. Then the two separate and both ants keep on pursuing their 
course. The typical response of alerted ants to a strong alerting stim- 
ulus consists of raising their gasters after the first few strokes (Fig. 
2, No. 4) of the recruiter’s head. They most often spread their 
mandibles, sometimes during the whole performance. Both partners 
contact their antennae in a vibrating way. After separation, alerted 
ants usually follow their general direction on the bridge, slightly 
excited and performing a zigzag run, often moving in circles or small 
loops into areas adjoining the trail (Fig. 3). After a few seconds of 
this excited dashing, however, their behavior changes into accurate 
trail-following or seeking for the trail. They show an increased ten- 
