42 LONGEVITY OF ANTS. 



a few days, dying between the 16th and 20th. These 

 two ants, therefore, must have been five years old at 

 least. It is certainly curious that they should, after 

 living so long, have died within ten days of one 

 another. There was nothing, as far as I could see, in 

 the state of the nest or the weather to account for this, 

 and they were well supplied with food ; yet I hardly 

 venture to suggest that the survivor pined away for 

 the loss of her companion. 



Some workers of F. cinerea lived in one of my 

 nests from November 1875 to April 1882. 



Workers of F. fusca have attained the age of six 

 years in several of my nests, and in one of Lasius niger 

 brought in on November 30, 1875, there were no 

 queens ; and, as already mentioned, no workers have 

 been produced. Those now living (February 1883) are 

 therefore the original ones, and they must be more 

 than seven years old. 



The duration of life in ants is therefore much 

 greater than has been hitherto supposed. 



Though I lose many ants from accidents, especially 

 in summer, in winter there are very few deaths. 



I have given the following figure (fig. 2), which 

 represents a typical nest belonging to Lasius niger, 

 because it is a good instance of the mode in which 

 my ants excavated chambers and galleries for them- 

 selves, and seems to show some ideas of strategy. The 

 nest is, as usual, between two plates of glass, the outer 

 border is a framework of wood, and the shaded part 



