Animals that Set Traps 



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sap which exudes besides eating a certain quantity 

 of the layer of soft growing wood beneath the 

 bark. But it has been shown by experiments with 

 captives that when fed wholly or mainly upon this 

 sap the bird starves. The larger part of its 

 fare, in fact, must consist of insects, and some 

 naturalists believe that the primary object of 

 the woodpecker in digging his circles of holes 

 in the tree-bark is to form a bait for insects. 

 Certain it is, that as soon as the sap flows in- 

 sects gather and buzz in swarms about the 

 honeyed exudation, and that the bird returns 

 again and again during the day to his tree, gath- 

 ering the bugs that have been caught in the 

 sticky little cups or in the drippings on the bark, 

 or snapping them from the air, as he is very 

 skillful in doing. 



In Teneriffe two warblers, familiar in Great 

 Britain as the blackcap and the garden warbler, 

 are each accustomed to puncture the calyx of 

 certain large flowers, particularly those of the 

 hibiscus and. abutilon, causing a little sweet 

 liquor to exude from the nectarous juices of 

 the blossom. This is attractive to many small 

 *$ 149 



