60 THE ARGENTINE ANT. 



placed on the comparatively smooth floor of an infested building, 

 and when the ants were visiting it in large numbers a distance of 

 6 inches was measured off on one of the principal "trails." The rate 

 of travel of individuals over this 6 inches was then noted. Mr. Smith 

 foimd that the average time required to travel the 6 inches when 

 going to the food supply was 12^ seconds, or at the rate of 29 inches 

 per minute. When returning from the food, presumably with their 

 stomachs filled with sirup, the average time recpiired to travel the 

 6 inches was 21 seconds, or at the rate of 17 inches per minute. The 

 rapidity with which the foraging ants can travel (29 inches a minute, 

 or 145 feet ])er hour) explains their ability to keep thoroughly 

 patroled all of the walls, furniture, and other contents of a building 

 within their reach. It explains at the same time the reason for their 

 so quickly locating food supplies left accessible to them. 



The rate of travel over horizontal polished surfaces is, however, 

 much greater than that cited above. On a tiled floor or on the top 

 of a glass showcase their speed is two or three times as great as that 

 just given. In fact, it is ahnost impossible to capture the workers 

 on a tiled floor, so rapidly do they move. This same degree of speed 

 is not attained on vertical polished surfaces, such as window panes. 



STORAGE OP FOOD. 



Only to a very small extent do the workers of this species provision 

 their nests for future emergencies. They are given to carrpng let- 

 tuce seed, and perhaps other seeds, into their colonies at times, but 

 the bulk of these seed are used up in a short time, and in a few days all 

 have disappeared. Apparently the desire to carry in a full supply of 

 any desirable food is the cause for this storage, rather than any fixed 

 instinct toward providing the colony •udth permanent stores. In like 

 manner, when the ants have access to large amounts of granulated 

 sugar, the granules are carried into the nest and deposited in various 

 parts of the galleries, there being no place set aside, apparently, as a 

 granary or storehouse. Like the seeds above mentioned, the supply 

 of sugar is consumed within a few hours or a few daj^s after its 

 acquisition. Particles of meat are deposited in the galleries in simi- 

 lar manner, often to be neglected until they are too dry to be of much 

 service. Even when dried, however, they seem to furnish a relish or 

 variation in the diet, as workers may be seen, from time to time, 

 rasping off small shreds with their nuindibles and then masticating 

 these with apparent enjoyment. 



Liquid food, such as honeydew, sirup, etc., is not deposited any- 

 where in the nest, and if any liquid food is kept in reserve at all it is 

 merelv that which is retained in the stomachs of the workers. Appar- 



