VERMIN AND TRAPPING 81 
are as cheap as bicycles will the keeper be able 
to compete with rooks at finding eggs on anything 
like equal terms. Even then rooks would have 
the advantage: for what they cannot see through 
they can walk beneath easily, to say nothing of 
a theory that rooks, like all other creatures, have 
eyes that magnify, so that objects appear to them 
several times larger than to the eyes of men. In 
any case, the eyes of a rook are infinitely keener 
than those of a man. Some rooks are worse than 
others at stealing eggs and young game. I am 
certain that when once a rook has tasted an egg it 
never loses a chance of doing so again, and the 
older it gets the more cunning it becomes at 
finding eggs. You may be sure a rook is an 
experienced egg-thief when you see it beating 
along a hedge, or over a wood or a field, with 
bill pointing this way and that, as its eyes pry 
into everything. Evidently rooks find peewits’ 
eggs comparatively as difficult to find as do men, 
for they are to be seen quartering a peewit-haunted 
field only about a yard from the ground. 
To show how cunning and persevering rooks 
become in their search for eggs, when walking 
along a dense hedge I often have heard a flapping 
of dusky wings within, and so have ended the 
career of many an arch-robber of nests. This is 
good evidence that, with all their cunning and 
instinct of self-preservation, rooks do not reason, 
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