62 



PROCEEDINGS OP THE ACADEMY OP 



[1884. 



account of the annoying creatures. The same is true of the 

 grain harvest which comes later, the appearance of the swarms 

 continuing throughout August and into September. The ants, 

 however, do not sting, my informant averred, notwithstanding 

 their popular title of " the stinging ants." The nervous irrita- 

 tion produced by contact with such numbers is the chief annoy- 

 ance. Some horses show great excitement under the visits of 





Fig. 4. Stocking-Shaped Mound.— Colorado. 



the swarms, to which the more stolid mule is quite indifferent. 

 These flying ants do not get angry when beaten off, and rush at 

 and follow after the parties attacking them as bees do; they 

 whirl round and round in dense masses^ alight upon an object 

 within their path, but show no sign of hostility or wish to pursue 

 human or other animals who approach them. The family of ants 

 to which this genus {Formica) belongs, has no members possessed 

 of true aculeate organs. The so-called "sting" is reallj^ pro- 

 duced by the insect " biting " or abrading the skin with its 

 mandibles, and then ejecting formic acid from its undeveloped 

 stinging organs into the wound. The smart of the acid is quite 

 severe. 



A Useful Insectivorous Habit. — Over against this annoyance 



