^I|e Canadian |Itttam(Jlogt$t. 



Vol. XLIX. 'LONDON, JULY, 1917 No. 7 



POPULAR AND PRACTICAL ENTOMOLOGY. 



The Death-Feigning Instinct. 



by e. melville duporte, macdonald college, que. 



Many widely diflferent animals possess the instinct of feigning 

 death. The sand-hopper, a terrestrial amphipod, and the pill-bug 

 {ArmadilUdium) are well-known examples among the Crustacea. 

 That many Myriapods will coil up and remain perfectly still on 

 being touched is well known to all acquainted with the habits 

 of the common millipedes. Among the spiders, the Epeirid^e or 

 orb-weavers are perhaps the ones which most commonly feign 

 death on being disturbed. 



Though rare the instinct occurs among the vertebrate animals. 

 Certain fishes and amphibians are known to feign death. Two 

 noteworthy examples of death-feigning birds are the partridge of 

 the pampas of the Rio de la Plata and the tern of Pekinese Island. 



Among mammals one of the best known examples is that which 

 has enriched the "American language" with the expressive term 

 "playing 'possum." Other well known examples are the fox and 

 the armadillo. 



It is among insects, how^ever, that the death-feigning instinct 

 is most widely distributed, especially among the Coleoptera and 

 Hemiptera. The active flyers such as the Diptera, H^^menoptera 

 and Lepidoptera seldom feign death. 



The term "feigning death" — an unfortunate one as it connotes 

 a consciousness which does not exist — is used to designate the 

 assumption by an animal, when disturbed, of a rigid state which 

 may be of momentary duration or may last upwards of an hour. 

 The attitude of the feigning animal varies, but is very seldom the 

 same as the attitude of the dead insect. The motionless con- 

 dition and the rigidity due to the contraction of the muscles are 

 the chief characteristics of the death feint, and for this reason I 

 have included under the term all rigid motionless attitudes which 

 are the result of a reaction to a shock stimulus. Given so broad 



