152 HABITS AND INSTINCTS OF ANIMALS. CHAP. V, 



2d, by noises; 3d, by scents; 4th, by emission of 

 fluids ; 5th,, by weapons ; 6th, by stratagem or con- 

 cealment. 



(17S.) The attitudes which insects assume, either to 

 screen themselves from observation, or to terrify their 

 enemies, are very remarkable. Among the means re- 

 sorted to for the first of these purposes, is that of 

 imitation. Mr. Kirby mentions a Staphylinus, or rove 

 beetle, which he at first mistook for a very minute 

 shining round pebble ; this appearance was produced 

 by the insect folding its head under the breast, and 

 turning up its body over the wing-cases. The Silfiha 

 thoracica Lin. {fig. 50.), when 

 50 -r^S3RESt^ alarmed, has recourse to a similar 

 manoeuvre ; in which state, the 

 colours being black and yellow, 

 the insect looks like a rough 

 stone. Many of the weevil 

 beetles (CurcuUonidce), particu- 

 larly those with short thick bodies, on the least appearance 

 of danger, gather themselves into a heap, bend their 

 snout under the thorax, and fall to the ground from the 

 plants upon which they happen to be feeding. It is 

 then in vain to search for them ; for, the colours being 

 perfectly matched to those of the ground, the keenest 

 eye will be completely baffled. There is a genus of 

 this family, found in the sandy tracts of Africa and of 

 Sicily, which, although large, is so exactly coloured 

 like the sand, that few entomologists would distinguish 

 the insects from the surrounding soil. One of the 

 most singular attitudes of this sort is that assumed by 

 nearly all the onisciform types of annulose animals, 

 and by many of those in the vertebrated circle ; it is 

 that of rolling themselves up in a perfectly spherical 

 ball, like the common woodlouse : in this attitude the 

 legs and all the softer parts of the body, on the under 

 side, are entirely covered and defended by the hard 

 crust which forms the upper surface of the animal. 

 Other insects endeavour to protect themselves, from 



