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Page:Popular Science Monthly Volume 72.djvu/187

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183
THE INSTINCT OF FEIGNING DEATH

same way. Among spiders death-feigning is not uncommon, especially among the orb weavers.

It is among the insects that the death-feigning instinct reaches its fullest development, occurring to a greater or less extent in most of the orders. It is especially common in beetles and not unusual among the bugs, but it is quite rare in the highest orders such as the Diptera or flies, and the Hymenoptera, or the ants, bees and their allies. It occurs in a few cases among butterflies and moths, both in the imago as well as the larval state. The instinct is exhibited in different species in all stages of development from a momentary feint to a condition of intense rigor lasting for over an hour. Some insects may be severely mutilated, or, according to De Geer, even roasted over a fire before they will cease feigning.

Among the vertebrate animals death-feigning has been observed only rarely in the fishes. In the Amphibia it is not exhibited in the striking way it occurs in insects and spiders, although frogs and toads may be thrown by the proper manipulation into an immobile condition more or less resembling it. A phenomenon apparently related to the death feigning of insects has long been known in certain reptiles. Darwin in his "Journal of Researches" describes a South American lizard which when frightened "attempts to avoid discovery by feigning death with outstretched legs, depressed body, and closed eyes; if further molested it buries itself with great quickness in the loose sand." The Egyptian snake charmers by a slight pressure in the neck region are able to make the asp suddenly motionless so that it remains entirely passive in the hands of the operator. And similar phenomena have been found in other species.

In birds the instinct crops out only here and there. A few summers ago when on the island of Penikese I was somewhat surprised to find the instinct well developed in the young terns which were hatched out in abundance on the hillsides. For a short time after being hatched the little downy fellows betray no fear of man and will cuddle under one's hand in perfect confidence. When the birds become larger and acquire their second coat of feathers the instinct of fear takes possession of them and they run and hide in the grass when you approach. Here they lie perfectly quiet; you may pull them about, stretch out their legs, necks, or wings and place them in the most awkward positions, and they will remain as limp and motionless as if really dead. They will even suffer their wing or tail feathers to be plucked out one by one without a wince. But all of a sudden the bird becomes a very different creature. It screams, pecks and struggles to escape. I have made several attempts to make a bird feign death a second time, but never met with success. According to Couch the land rail and skylark feign death, and Wrangle states that the wild geese of Siberia have the same habit during their molting season, when they are unable