THE ARGENTINE ANT. 57 
GENERAL OBSERVATIONS. 
AVERSION TO LIGHT. 
The ants demonstrate in many ways their dislike of light, or at 
least their aversion to it. Their nests are always located in dark 
places, the ants are active all night, and their immature stages are never 
exposed to light except for brief periods in emergencies. If the 
opaque cover is removed from the top of an artificial ant nest for a 
considerable time, all the ants will come out and will refuse to return 
until the cover is replaced. Several experiments were made at 
Baton Rouge, La., in 1909, using different colored glasses for cage 
covers, but the ants were not satisfied unless the cover was absolutely 
opaque. While they will go anywhere into daylight in search of 
food, they will cover over as thoroughly as possible, with their 
protective "sheds," the colonies of scale insects, mealy-bugs, and 
aphides which they habitually frequent. 
SENSE OF SMELL. 
The workers exhibit a very keen sense of smell by the manner 
in which they locate certain foods. Meat which is wrapped in heavy 
wrapping paper will attract thousands of the insects, and they will 
work their way through the various folds and crevices of the paper 
in a surprising manner until they reach the meat itself. The workers 
readily secure entrance into the ordinary Mason or glass fruit jar, 
if one omits placing beneath the cover the rubber ring or gasket. 
No matter how tightly the cover is screwed on, the workers follow 
the spiral threading between cover and glass until the interior is 
reached. 
Another illustration of the sense of smell is seen in the readiness 
with which trails are restored when broken or disturbed. If a line 
of ants be moving across a floor in a circuitous line, for example, 
and all ants be swept from the floor with a broom, the next on-coming 
workers will follow exactly t h " . .iginal course. This may be repeated 
indefinitely and the trail will always be established in the original 
location. If, however, some strong-smelling substance, like oil of 
citronella or kerosene, be placed upon the trail the ants become 
confused at once and by their aimless wandering about show plainly 
that they can not locate the original pathway. 
While the Argentine ants are extremely sensitive to light, it is 
doubtful if they possess the sense of sight. The action of light can 
generally be described as exerting a repelling influence upon them 
and they avoid it as much as they can. That they do not use eyesight 
in locating food substances has long been recognized. Their trails 
