39 



others were just outside on the edge of the nest, and the remainder on 

 one corner of the base. Most of the larvae had been carried out, al- 

 tho a number between an eighth and a fourth of an inch from the 

 tar had been left. (Fig. 16. ) There was no return laf the ants to this 

 nest up to March 11,6 days after the experiment was started. During 

 all this period the colony stayed together on a distant corner of the 

 base, so closely packed that a number were crowded off into the sur- 

 rounding water every day and drowned. When the experiment closed. 

 March 11, only about sixty ants were alive. 



Experiment 5790, Vaporite. — March 5, at 11:30, a bit of moist 

 vai:)orite at the center of a nest disturbed the ants but did not repel 

 them violently. They were mostly outside the nest together with their 

 larv?e when this was established, and by 3:15 only half a dozen ants 

 had gone under the cover. The rest remained outside until 10:45 the 

 following day, when about twenty were seen at one corner of the nest 

 two and a quarter inches from the repellent. By 4:15 of that after- 

 noon (28 hours, 45 minutes), tiiere were about fifty ants in the nest, 

 the nearest one and a half inches from the vaporite, but all the larvae 

 were still outside on the base. The ants now gradually returned, bring- 

 ing their larvae with them, until at 9 a. m. of March 7 they were all 

 in the nest. The repellent was not removed until 8: 45, March 11, nearly 

 six days after the experiment was begun. /\t this time the ants nearest 

 the vaporite were three-eighths of an inch away. 



Experiment 5791, Vermicide. — A])ril 14, at 8:15 a. m., sand 

 soaked with vermicide and tested on a fresh colony, wbich had been in 

 the cage for five days only from the field, drove them out in less than 

 a minute, many of their larv?e being left behind together with five of 

 the workers which had touched the vermicide and had then died. In 

 fifteen minutes the ants were beginning to carry their larvae out from 

 under the cover, and piling them along the border of the nest, as 

 shown in the following sketch (Fig. 17). By 3 p. m. there was 

 nothing in the nest except some deserted larvae (Fig. 18), and these 

 conditions remained unchanged until two days had elapsed, when at 

 8 : 50 a. m. April 16, a 4 X 4 cover was substituted for the smaller one. 

 The ants paid no attention to this change, and the next day at 8 : 20 

 a. m. a still larger orange cover 5X6 inches was put in place. This 

 brought certain of the ants under its protection at one corner, and 

 others moved under slowly until at 9: 30 about one-third of the colony 

 were in the nest, the nearest two and a fourth inches from the repel- 

 lent. This condition remained practically unchanged until 11 : 25 April 

 19 (5 days, 3 hours), when the small orange cover with which the ex- 



