154 
Psyche 
[September 
next move was to see if this liquid was used by the adult for food, 
or if it was collected, a drop at a time, and placed with the eggs 
in other new cells. Wheeler says that the females feed the young 
in exchange for the saliva which they emit at the time of feeding, 
but here we saw the saliva emitted long after they had been fed. 
I wonder if a worker can get a drink whenever it taps the head 
of a larva just as I can cause a large drop to come by teasing it 
with the head of a pin. 
On one occasion two foster queens, after feeding the larvae, 
went into the cells after sounding a noisy warning, evidently 
for the purpose of obtaining saliva. I watched very closely, and 
this time was able to see the method. The queen (so she will 
henceforth be called) stood on a nest with her head at the opening 
of a cell and her antennae inside, probably touching the larva. 
Her head was then rapidly rammed or beaten against the wall 
of the cell; the whole body was in motion, seeming to actuate 
the head, and this rapid vibration of the head against the paper 
wall caused the strange sound. In one cell this drumming was 
repeated six times, and the duration of each round of it was one- 
fourth to one-half minute. After each trial the queen thrust her 
head into the cell, but obtained no saliva. I too could peer in by 
coming close beneath the nest, and there I found that after each 
serenade by the queen, the mouthparts of the larva were in 
agitated motion as if making effort, and a very small, glistening 
drop appeared on the mouth. In all probability the amount was 
not sufficient to satisfy the demands of the queen, for only after 
the sixth trial did she thrust her head far in and keep it there. 
These noises must have stimulated some others near by, for 
they too responded with a glistening drop in the mouth; into 
one of these cells she entered without the preliminary music. 
In most of the others, however, the warning was given but once. 
The queen’s antennae probably also acted as a stimulus, but her 
body always obstructed my view at that moment so I could not 
clearly see this. This first foster-queen had no exclusive patent 
rights on this scheme, for the second one used precisely the same 
methods. 
This fact that the honey-dew, coming from the mouths of 
the larvae, is lapped up and relished by the workers, is not new, 
