NOISES OF INSECTS. 489 



without interrupting its song. The giant cock-roach (Slatta gigantea) 

 which abounds in old timber houses in the warmer parts of the world 

 makes a noise when the family are asleep like a pretty smart rapping with 

 the knuckles three or four sometimes appearing to answer each other. 

 On this account, in the West Indies it is called the Drummer; and they 

 sometimes beat such a reveille, that only good sleepers can rest for them. 1 

 As the animals of this genus generally come forth in the night for the pur- 

 pose of feeding, this noise is probably connected with that object. 



Insects also, at least many of the social ones, emit peculiar noises while 

 engaged in their various employments. If an ear be applied to a wasps' or 

 humble-bees' nest, or a bee-hive, a hum more or less intense may always 

 be perceived. Were 1 disposed to play upon your credulity, 1 might tell 

 you with Gcedart, that in every humble-bees' nest there is a trumpeter, 

 who early in the morning, ascending to its summit, vibrates his wings, and 

 sounding his trumpet for the space of a quarter of an hour, rouses the in- 

 habitants to work! But since Reaumur could never witness this, I shall 

 not insist upon your believing it, though the relater declares that he had 

 heard it with his ears, and seen it with his eyes, and had called many to 

 witness the vibrating and strepent wings of this trumpeter humble-bee. 8 

 The blue sand-wasp (Ammophila? cyanea), which at all other times is 

 silent, when engaged in building its cells, emits a singular but pleasing 

 sound, which may be heard at ten or twelve yards' distance. 3 



Some insects also are remarkable for a peculiar mode of calling, com- 

 manding, or giving an alarm. I have before mentioned the noise made by 

 the neuters or soldiers amongst the white ants, by which they keep the 

 labourers, who answer it by a hiss, upon the alert and to their work. 

 This noise, which is produced by striking any substance with their man- 

 dibles, Smeathman describes as a small vibrating sound, rather shriller and 

 quicker than the ticking of a watch. It could be distinguished he says at 

 the distance of three or four feet, and continued for a minute at a time 

 with very short intervals. When any one walks in a solitary grove, where 

 the covered ways of these insects abound, they give the alarm by a loud 

 hissing, which is heard at every step. 4 " When house-crickets are out,'* 

 says Mr. White, " and running about in a room in the night, if surprised by 

 a candle, they give two or three shrill notes, as it were for a signal to their 

 followers, that they may escape to their crannies and lurking-holes to avoid 

 danger." 5 



Under this head I shall consider a noise before alluded to, which has 

 been a cause of alarm and terror to the superstitious in all ages. You will 

 perceive that I am speaking of the death-watch so called, because it emits 

 a sound resembling the ticking of a watch, supposed to predict the death of 

 some one of the family in the house in which it is heard. Thus sings the 

 muse of the witty Dean of St. Patrick on this subject : 



** A wood-worm 



That lies in old wood, like a hare in her form : 



* Drury's Insects, iii. Preface. 



8 Lister's Gcedart, 244. Compare Reaum. vi. 30. 



5 Bingley, Animal Bioc/r. iii. 1st ed. 335. Mr. Westwood has also observed the 

 same peculiarity in Ammophila hirsuta whilst similarly engaged. 



* Philos. Trans. 1781, 48. 38. Nat. Hist. ii. 262. 



