DO ANIMALS THINK AND REFLECT? 



for her nest. She hopped to this tangle of shoots and 

 sat down, then to that, she turned around, she re- 

 adjusted herself, she looked about, she worked her 

 feet beneath her, she was slow in making up her 

 mind. Did she make up her mind ? Did she think, 

 compare, weigh ? I do not believe it. When she 

 found the right conditions, she no doubt felt pleasure 

 and satisfaction, and that settled the question. An 

 inward, instinctive want was met and satisfied by an 

 outward material condition. In the same way the 

 hermit crab goes from shell to shell upon the beach, 

 seeking one to its liking. Sometimes two crabs fall 

 to fighting over a shell that each wants. Can we 

 believe that the hermit crab thinks and reasons ? It 

 selects the suitable shell instinctively, and not by an 

 individual act of judgment. Instinct is not always 

 inerrant, though it makes fewer mistakes than reason 

 does. The red squirrel usually knows how to come 

 at the meat in the butternut with the least gnawing, 

 but now and then he makes a mistake and strikes the 

 edge of the kernel, instead of the flat side. The cliff 

 swallow will stick her mud nest under the eaves of a 

 barn where the boards are planed so smooth that the 

 nest sooner or later is bound to fall. She seems to 

 have no judgment in the matter. Her ancestors built 

 upon the face of high cliffs, where the mud adhered 

 more firmly. 



A wood thrush began a nest in one of my maples, 

 as usual making the foundation of dry leaves, bits 

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