CHAPTER III 



EXCHANGING THE NESTS 



LET US continue our series of tests with 

 the Mason-bee of the Walls. Thanks to 

 its position on a pebble which we can move at 

 will, the nest of this Bee lends itself to most 

 interesting experiments. Here is the first: I 

 shift a nest from its place, that is to say, I 

 carry the pebble which serves as its support 

 to a spot two yards away. As the edifice and 

 its base form but one, the removal is per- 

 formed without the smallest disturbance of the 

 cells. I lay the boulder in an exposed place 

 where it is well in view, as it was on its 

 original site. The Bee returning from her 

 harvest cannot fail to see it. 



In a few minutes, the owner arrives and 

 goes straight to where the nest stood. She 

 hovers gracefully over the vacant site, ex- 

 amines and alights upon the exact spot where 

 the stone used to lie. Here she walks about 

 for a long time, making persistent searches; 

 then the insect takes wing and flies away to 

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