ENGINEERING METHODS 



yet another. None of these attempted to help the gate- 

 closers, who slowly and steadily filled up the entrance. 



Now occurred the usual side-play with late-comers. 

 At 7.07 a straggler came along and tried to get in. As 

 the gate was nearly closed, she deliberately proceeded 

 to break it open. A pebble was taken from the gate- 

 covering and carried three inches up the mound. An- 

 other was tugged still farther up, and yet another. 

 Then in steps the gate-closer, quite undisturbed by the 

 counter-working of her fellow, and quietly plugs up the 

 little break made with a big pebble, and slips within at 

 a by-cranny that had escaped the straggler's notice. 



A second straggler appears while the closers are ad- 

 justing the material from within, as may be seen by the 

 agitation of the surface. Meanwhile the first straggler 

 has grappled with the last big pellet dumped, which she 

 succeeds in dragging aside of which straggler number 

 two takes advantage, and steps into the nest. There- 

 upon one of the closers reappears from the inside, and, 

 without the least token of vexation at thwarted plans, 

 restores the piece to its place and returns. 



Straightway the first straggler renews her opposition 

 effort, and has just set the pebble aside when a small 

 black beetle comes up. This the straggler seizes, puts 

 down, turns, reseizes, and tries to push into the gate 

 therewith. The beetle, however, escapes; and the for- 

 aging instinct which led the straggler to forego for the 

 nonce her house-breaking is not strong enough now 

 to divert her from the home trail. So beetle goes her 

 way unpursued and the contrarious straggler disappears 

 inside. 



At 7.20 a gate-closer comes out and adjusts several 

 pebbles. My imperfect perceptions cannot discern the 



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