170 



COMMERCIAL POULTRY RAISING 



trigger. When the hen enters, she pushes against the door with 

 her back; this disengages the trigger, allowing the door to close 

 after her, and by the same operation locks the door from within, 

 — for the trigger has simultaneously assumed a horizontal posi- 



Treadle set with door open to admit hen. 



Treadle sprung — door closed. 

 Fig. 1 19. — Details of the Maine trap nest. 



tion. Small wooden buttons or bent screw-eyes are screwed to 

 the partitions, turned in such a manner as to prevent the doors 

 swinging outward when the nest is sprung. To open the nest, 

 the attendant has but to turn the little button, open the door 

 outward, and remove the hen. 



