FORMICA. 249 



Bowman says that the sense of hearing in this species is very 

 acute; he instances the "clapping of hands" 49 and the "buzzing 

 of a fly " 50 being noticed at once, and he gives some not very con- 

 vincing experiments to prove his point. Clarke also mentions that 

 when he kicked a fir tree on which were a number of rufa workers, 

 instantly every vagrant ant suspended its operations and leant for- 

 ward with the antennae porrect as though they were listening to 

 discover the cause of the annoyance 11 . These cases do not illus- 

 trate hearing in our sense of the word, but rather reaction to 

 material vibrations. I have tested F. rufa (and other ants) in 

 captivity with the Galton-Edelmann whistle, up to its highest 

 range, but the ants never appeared to notice anything. 



F. rufa recognizes its fellows both from the same nest, and 

 from the same community, after having been separated for long 

 periods. 



On April 2nd, 1901 (not " 1907 " 78 ), I established a nest of 

 Formica rufa, from Oxshott, in my study, containing twelve 

 females and many workers, etc., and on April 12th I brought home 

 from the same nest at Oxshott some more females and workers and 

 introduced them into my observation nest, when they were at once 

 recognized and received with pleasure, the females being cleaned 

 and led into the nest. On April 26th I brought home a female and 

 some workers from another nest at Oxshott, far removed from the 

 first nest, and these also were well received by the ants in the 

 observation nest. I have also been in the habit of obtaining ants 

 in the spring from the same rufa nests from which I had previously 

 taken specimens to form observation nests at home, and intro- 

 ducing them into the latter. I extract the following from one of 

 my note-books " May 19th, 1907. Took part of a nest of F. rufa 

 at Weybridge " ; then later on, " April 7th, 1908. Got some 

 more debris from the same nest at Weybridge, 4 $$, g , etc. ; 

 ants all well received." 78 



As an instance of tenacity of life, an experiment made by Janet 

 may be mentioned in which a rufa worker lived without a head for 

 twenty-nine days 60 . 



This species nests in woods in shady places, in clearings, and on 

 the borders of woods and forests but also in the interior on 

 heaths and commons, but never far from trees, being more generally 

 associated with fir trees, though it also occurs in oak, birch, and 

 other woods. Forel states that in the Alps it is intimately connected 

 with the fir trees, occurring as high as the last of these, but never 

 higher 37 . 



F. rufa usually avoids the neighbourhood of human habitations, 

 but will enter gardens in search of its prey and other food. 



Its nests principally consist of the well-known mounds or hillocks 

 forming a conical structure on the ground, covering an earth mound 

 crater at the base, these structures being built up of pine needles, 



