74 METHODS OF ATTRACTING BIRDS 



to nest so early, may be entirely neutralized either 

 by taking down the houses in the fall and not 

 putting them up till the birds return in the 

 spring, or by covering up the holes after the 

 birds are through with the nest, and keeping the 

 cover on till the nesting-time of the bird which we 

 wish to induce to nest there. Or, as previously 

 suggested, we may let the sparrows nest early and 

 try to discourage them before the other birds are 

 ready. 



Small Holes, — There is considerable satis- 

 faction in being able to record one device which 

 is almost entirely successful in keeping out the 

 sparrows, and that is, making the hole so small 

 that the sparrows cannot enter, but large enough 

 for the wrens and chickadees. An inch hole is 

 large enough for the wren, and keeps out the spar- 

 rows ; an inch and an eighth will do for the 

 chickadee, and will usually keep out the sparrow, 

 although the author finds observations recorded 

 in which the sparrow entered even this size ; but 

 this is probably exceptional. Even with the wren- 

 houses there may occasionally be a little trouble. 

 In one case the sparrow was seen to enlarge the 

 hole till it was large enough for it to enter. In 

 a few cases the sparrow is reported as staying 

 around the house and troubling the wrens as they 



