182 OUR INSECT FRIENDS AND FOES 



and she flies backwards and forwards bringing 

 little pellets of mortar, small stones, and 

 particles of gravel which she works into the 

 structure with her mandibles and fore-feet until 

 a cell is completed. The bee then varies her 

 labours by collecting pollen and honey from the 

 flowers. These she mixes into a cake, inside the 

 cell; first she puts her head in and disgorges 

 the honey from her bag, and then she goes in 

 backwards, and brushes the pollen from the 

 under surface of her body with her two hind 

 feet. Every now and then, when she has added 

 some more honey and pollen to the store, she 

 stirs it together into a mass with her mandibles ; 

 then when the cell is about half full of this sweet 

 food, she lays an egg on the top of it and closes 

 it up. Several cells, varying in number from six to 

 twelve, are made close together, and then the bee 

 builds a thick roof of mortar over them all, so 

 that the nest when finished looks like a lump of 

 mud stuck on the wall. 



The Chalicodoma do not always build new 

 nests, but often economize labour by utilizing 

 the more or less broken-down old ones, that 

 remain attached to the walls. These the bees 

 thoroughly clean and repair, clearing out the 

 remnants of old cocoons that still hang on the 

 walls, and stopping up all cracks with a little 

 fresh mortar. Sometimes it happens that a 

 Mason Bee on the look-out for an old nest, or a 

 suitable site on which to construct a new one, 

 comes upon a nest belonging to another bee, and 

 endeavours to annex it. This the rightful owner 

 naturally resents, and a fierce fight takes place 



