THE INSTINCT OF FEIGNING DEATH 179 



THE INSTINCT OF FEIGNING DEATH 



By Professor S. J. HOLMES 



UNIVERSITY OF WISCONSIN 



THE so-called instinct of feigning death is one which is very widely 

 distributed in the animal kingdom. It crops out sporadically, 

 as it were, in forms which are but very distantly related, and hence it 

 must have been independently evolved a great many times. The ex- 

 pression feigning death is a misleading one to the extent that it is apt 

 to give rise to the idea that the animal consciously adopts this device 

 with the intent to deceive. While it is probable, however, that among 

 the higher animals which sometimes feign death there may be an 

 attempt to mislead their enemies, it is quite certain that among the 

 insects, spiders and other low forms there is no such aim in the 

 creature's mind if we grant (what some naturalists are disposed to 

 deny) that these animals have minds. The veteran French naturalist, 

 Fabre, who has devoted the leisure periods of a long life to the enthusi- 

 astic study of the ways of insects, performed several experiments on 

 beetles in order to ascertain if the duration of their feint was in any 

 way affected by his own presence or movements. Most of Fabre's ob- 

 servations were made on a large scarab beetle. When handled the 

 beetle would throw itself into an immobile state with its head bent 

 down and its legs drawn in close to the body. It would remain in this 

 attitude perfectly quiet for several minutes — sometimes for over an 

 hour. Its awakening would be first manifested by a slight trembling 

 of the feet and a slow oscillation of the antennas and palps ; then its 

 legs would move about more vigorously, and finally the insect would 

 arise and scamper off. Seized again, it would repeat the performance 

 several times in succession, the duration of the feint often increasing 

 with successive trials. Finally, as if wearied, or convinced that the 

 ruse were vain, the beetle would refuse to feign longer. 



Were the feints attempts to deceive its captor by simulating death ? 

 Fabre placed the insect on its back, went to a distant part of the room 

 and remained perfectly quiet. The beetle still lay as usual. He then 

 went out of the room, carefully looking in at intervals to watch the 

 course of events. Still the same immobility. In other cases he cov- 

 ered the insect so that it could not see out and then quietly went away. 

 This was also found to make no difference. In fact, whether the insects 

 were surrounded by sounds and sights of moving objects or entirely 

 excluded from these influences made no difference in the average length 



