334 ENTOMOLOGY 
that kings of one colony of Stenamma when introduced into 
another colony are even cordially received. 
Some of the most careful students of the habits of ants agree 
that these insects can communicate with one another. An ant 
discovers a supply of food, returns toward the nest, meets a 
fellow worker, the two stroke antennz and then both start 
back to the food; before long other members of the colony 
swarm to the prize. It has been thought that the odor of the 
food or some other odor, left by the first ant, serves as a trail 
for the other ants to follow. Bethe, indeed, infers from his 
experiments that this phenomenon is purely mechanical and 
involves no psychical qualities on the part of the ants. His 
awn experiments, however, show that one ant can inform an- 
other by means of an odor as to the whereabouts of food— 
which is certainly one form of communication. 
Ants avoid sunlight as a rule but prefer rays of lower re- 
frangibility to those of higher. Upon exposing ants to the 
colors of the spectrum, as transmitted through glasses of dif- 
ferent colors, Lubbock found that they congregated in greatest 
numbers under the red glass and that the numbers diminished 
regularly from the red to the violet end of the spectrum, there 
being very few individuals under the violet glass. 
Miss Fielde, experimenting with queens, workers and young 
of Stenamma fulvum piceum in an artificial nest, covered halt 
the nest with orange glass and half with violet. ‘* The ants re- 
moved hastily from under the violet as often as an interchange 
of the panes was made, once or twice a day, for about twenty 
days. ‘Thereafter they became indifferent to the violet rays.” 
“The plasticity of the ants is remarkably shown in their grad- 
ually learning to stay where they were never disturbed by me, 
under rays from which their instincts at first withdrew them.” 
Ants are sensitive not only to the different colors of the 
spectrum but also to the ultra-violet rays, which produce no 
appreciable effect on the human retina (though they induce 
chemical changes). If obliged to choose between the two, ants 
prefer violet to ultra-violet rays, as Lubbock found. If, how- 
