THE ECONOMIC VALUE OF BIRDS 

 boys, care for and perpetuate plant lice which infest 

 vegetation in all parts of the country to our very 

 serious loss. Professor Forbes, in his study of the 

 corn plant louse, found that in spring ants mine 

 along the principal roots of the corn. Then they 

 collect the plant lice, or aphids, and convey them 

 into these burrows and there watch and protect 

 them. Without the assistance of ants, it appears 

 that the plant lice would be unable to reach the roots 

 of the corn. In return for these attentions the ants 

 feast upon the honey-like substances secreted by 

 these aphids. The ants, which have the reputation 

 of being no sluggards, take good care of their di- 

 minutive milch cattle, and will tenderly pick them up 

 and transport them to new pastures when the old 

 ones fail. Late in the summer they carefully collect 

 all the aphid eggs that are obtainable, and taking 

 them into their nests keep them safe during the win- 

 ter. When spring comes and the eggs hatch, the 

 ants gather the young plant lice and place them on 

 plants. It may be seen, therefore, that the Flicker 

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