34 BRITISH INSECTS 



regular tapping noise by knocking its jaws or head 

 against woodwork. Whether this is indeed the case 

 remains an open question, although several competent 

 observers attest it as a fact. One or two other wing- t 

 less forms of Corrodentia are sometimes found in houses, 

 while certain winged species are very common out of 

 doors. The latter frequent the trunks and branches 

 of trees some kinds preferring dead wood and feed 

 on lichens and fungi. Numbers of these tiny creatures 

 may be captured during the summer months by the 

 simple process of shaking a branch over a sheet of 

 paper. 



The " book-lice " and their near relatives 1 make up 

 the sub-order Copeognatha of the Corrodentia. The 

 second sub-order 2 comprises the remarkable parasites 

 commonly called " bird-lice." These insects, which 

 must not be confused with their repulsive blood- 

 sucking namesakes mentioned in a succeeding chapter 

 (p. 54), feed on the delicate parts of the feathers or 

 hairs, and the dried secretions of the skin, of their 

 "host" Most of the species live among the feathers 

 of birds,]. but a few are found upon mammals. One 3 

 occurs upon^dogs. These Mallophaga have relatively 

 large, hard heads and flattened bodies, while their 

 mouth-parts are lodged in a special cavity. Many 

 kinds lay ^strangely shaped and beautiful eggs, which 

 are much in demand as objects for the microscope. 



The sixth order of British insects viz., Ephemerop- 

 tera has been constituted for the benefit of the 

 May-flies, 4 whose relationship to other insects remains 

 very obscure. In adult May-flies the mouth-parts are 

 abortive or obsolete, while the digestive track is also 



1 PsocidcB. 2 Mallophaga. 



3 Trichodectes latus. 4 Ephemerida. 



