WHAT DO ANIMALS KNOW? 
filled the nest, crowding out the bird. If the bird 
could have foreseen the danger, she would have 
shown something like human reason. 
Birds that nest along streams, such as the water- 
thrush and the water-ouzel, I suppose are rarely 
ever brought to grief by high water. They have 
learned through many generations to keep at a safe 
distance. I have never known a woodpecker to drill 
its nesting-cavity in a branch or limb that was ready 
to fall. Not that woodpeckers look the branch or tree 
over with a view to its stability, but that they will cut 
into a tree only of a certain hardness; it is a family 
instinct. Birds sometimes make the mistake of 
building their nests on slender branches that a sum- 
mer tempest will turn over, thus causing the eggs or 
the young to spill upon the ground. Even instinct 
cannot always get ahead of the weather. 
It is almost impossible for us not to interpret the 
lives of the lower animals in the terms of our own 
experience and our own psychology. I entirely agree 
with Lloyd Morgan that we err when we do so, 
when we attribute to them what we call sentiments 
or any of the emotions that spring from our moral 
and esthetic natures, —the sentiments of justice, 
truth, beauty, altruism, goodness, duty, and the 
like, — because these sentiments are the products 
of concepts and ideas to which the brute natures 
are strangers. But all the emotions of our animal 
nature — fear, anger, curiosity, local attachment, 
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