36 THE ARGENTINE ANT. 
In February, 1908, the senior author constructed, on the grounds 
of the Louisiana Experiment Station at Baton Rouge, a small build- 
ing for the purpose of studying this ant more in detail. The building 
was 10 by 30 feet and equipped with benches having upon them gal- 
vanized iron trays 2\ by 12 feet, 4 inches deep. In these trays the 
cages were placed and by means of suitable connections running 
water 2 inches in depth was kept passing through the trays day and 
night. As the ants would not voluntarily enter running water this 
arrangement worked admirably. The interior arrangement of this 
building is shown in Plate III. The iron trays and ant cages are 
shown upon the right, with work tables, chemicals, etc., on the left. 
The building was equipped with electric and extension lights for 
night examinations, and a combined thermograph and hygrograph 
recorded the temperature and humidity of the room at all times. 
For convenience this building was referred to as the "formicarium. " 
Plenty of windows insured full ventilation at all seasons, and to avoid 
abnormally high temperature in summer a second or accessory roof 
was placed two feet above the main roof. This laboratory also 
proved a convenient insectary for the rearing of other insects. 
The Argentine ant possesses a marked proclivity for attacking all 
insects which one has under observation, and all rearing experiments in 
cages, no matter what the insect, must be protected from the ants. 
The trays of running water therefore served to keep the ants away 
from general cage experiments as well as to confine them to the cages 
in which they themselves were being studied. 
ESTABLISHING COLONIES FOR STUDY. 
To establish a colony in one of the artificial formicaries or cages is 
comparatively easy. It is only necessary to secure a fertile queen 
from some thriving outdoor colony and place her on the stand, first 
placed in water, together with any desired number of workers which 
have been captured by attracting them to a sweetened sponge or 
piece of fresh meat. Any lot of workers will accept any queen and 
vice versa. When queen and workers are thus placed upon the cage 
and its stand, they usually, after a few hours, take up their abode 
in the nest proper. At first we experienced some difficulty in pre- 
venting them from collecting beneath the stand, but it was presently 
found that if a little dirt were removed from another colony and placed 
in the entrance of the new formicary the ants would enter at once and 
adopt it as a suitable home. After the establishment of such colonies 
the queen usually commences egg deposition in from 6 to 48 hours. 
By establishing colonies in this manner, without immature stages 
present, it is easy to observe the daily rate of egg deposition, the 
incubation period of the eggs, and the duration of the larval and pupal 
