8 ANTS. 



a consideration of all the facts forces us to admit, with Forel, that as 

 a group ants are eminently beneficial and that for this reason many 

 species deserve our protection. Some of our species, however, are cer- 

 tainly noxious, and tlu^e offer strong resistance to all measures for 

 their extermination/' owing to the tenacity with which they cling to 

 their nesting sites, their enormous fertility and the restriction of the 

 reproductive functions to one or a few queens that are able to resist 

 destruction by living in the inaccessible penetralia of their nests. 



The greatest usefulness of ants, which lies in their power to hasten 

 the decomposition of organic substances, is easily overlooked or belit- 

 tled, like all the great forces which act very gradually but incessantly. 

 Of the millions of insects annually born into the world, many are 

 undoubtedly consumed by insectivorous vertebrates, but a vast number 

 survive till they have provided for the next generation and then fall 

 exhausted to the earth. These, together with many that have just left 

 their pupal envelopes, or for other reasons are unable to escape, are 

 the natural food of most ants. A vast number of wingless and larval 

 insects, spiders, etc., thus fall a prey to these omnipresent and vigilant 

 free-booters. Let anyone who doubts these statements fix his attention 

 for an hour on some populous formicary during a warm summer day 

 and he will be astonished at the number of dead and disabled insects 

 carried in by the foraging workers. Forel observed that a large colony 

 of ants brought in 28 dead insects per minute and estimated that they 

 would bring in 1 00,000 daily during the hours of their greatest activity. 

 While this is certainly a high estimate and based on more than 28 per 

 minute, one half or one third of the number, which is well within the 

 bounds of probability, is certainly enormous. In the tropics this daily 

 consumption of insects must be vastly greater than in temperate regions, 

 and while the ants do not, of course, distinguish between the beneficial 

 and harmful insects that they kill, they probably dispose of more of 

 the latter. Eminent economic entomologists like Taschenberg and 

 Ratzeburg, who have studied the ants in the German forest preserves, 

 are of the opinion that they are highly beneficial. A German law, 

 passed in 1880, punishes with a fine of 100 marks or a month's impris- 

 onment any person who collects the cocoons of the fallow ant. Formica 

 ntfa, or wantonly disturbs its nests in the forest preserves. 



The driver ants (Dorylii) in the tropics of the Old World and the 

 allied legionary ants (Ecitonii ) in the corresponding regions of America, 

 do not confine themselves to collecting dead or disabled insects. They 

 move in long files over or immediately beneath the surface of the 



3 In Appendix D I have given a brief outline of the most approved methods 

 of destroying noxious ants. 



