CLOSING THE DOORS AT NIGHT 



preached by a long and tortuous passage that winds to a 

 distance of several feet through the grass. The smallness of 

 these doorways, which are always carefully guarded inside, 

 prevents the entrance of any insects or reptiles that might 

 otherwise creep in. 



During the day, when they are collected in crowds upon 

 the dome of their nest, the wood ants have no fear of being 

 disturbed inside ; but in the evening when they have retired to 

 their quarters, and can no longer perceive what is going on out- 

 side, how are they protected from the dangers by which they 

 are threatened ? And why does not the rain penetrate into 

 a dwelling which has doorways on all sides ? Naturalists do 

 not appear to have paid any attention to these simple ques- 

 tions. Can it be that they have not foreseen what misfortunes 

 would have happened to these ants if the wisdom which 

 governs the universe had not provided for their safety? 

 Struck with these reflections when I noticed the red wood 

 ants, I turned the whole of my attention to this subject and 

 was not long left in doubt. 



I noticed that the appearance of these ant-hills was con- 

 stantly changing, and that those roomy approaches where so 

 many ants could pass one another freely at midday became 

 gradually narrower towards night and at last disappeared 

 altogether : the dome was closed on all sides and the ants 

 retired to the bottom of their nest. 



By observing the ants' doorways for the first time, I got 

 a much clearer idea concerning the work of the inhabitants : 

 until then I had not been able to understand exactly what 

 object they had in view, for the surface of the nest presented 

 such a busy scene, and so many insects were occupied in 

 carrying materials in all directions, that the only impression 

 I had received was one of confusion. 



I then saw clearly that they were engaged in stopping up 



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