"Their real name is aphis, or plant-louse," said Uncle Ben. "They suck the juices of the leaves. These juices become in their bodies a sort of honey, which they yield from certain pores. The ants are very fond of this honey-dew, and lap it up eagerly. And if you watch close you may see them patting or stroking the aphides to make them yield the honey faster. That is what has been called milking their cows."
"Well, that is very curious, I know," exclaimed Harry. "I am going to watch them after this."
"Each ant seems to claim certain cows as his own property," continued Uncle Ben. "And he will bristle up angrily if any other ant strays into his pasture fields. But that is not the whole story. They not only milk these cows, but they tenderly raise their calves. Some species of the aphis live on the roots of plants. Around these the ants make their nests, so as to have their cows in stables of their own. And they take the greatest care of the eggs and the young of the aphides, raising them as tenderly as they raise their own young. No human farmer could be more careful of his own stock of cows and calves."
"You 'mos' might as well say they's folks right out," ejaculated Willie, indignantly. "Anyhow, it's ole honey, an' it ain't milk at all."
"I am sure it is not the fault of the ants if their cows give honey instead of milk," replied his uncle, with an odd smile. "And I have certainly seen folks who were not as wise as the ants."
"But never mind the cows, Uncle Ben," persisted Harry. "I want to hear about the foraging ants. Where do they belong, and what queer things do they do?"
"They are a South American ant," was the reply. "They may be seen at certain seasons marching along the ground in a long column, much like an army. They have officers, too. These are large-headed ants that march outside the column, and keep it in order. It is an immense army they command, I can assure you—greater than that with which Xerxes in old times invaded Greece; for there may be millions of ants in the line. There is another species which does not march in column, but in a close mass, often covering from six to ten square yards of ground."
"But what are they after?" asked Harry.
"That's jes what I wants to know," observed Willie, whose curiosity had returned.
"They are after food," replied their uncle. "It is amusing to see the insects scampering off from their line of march. They seem to know the danger that threatens them, for scarcely a living thing escapes the sharp jaws of these fierce foragers. They send out side columns to search the ground and the bushes and low trees. When any insect is found, it is instantly surrounded and covered by these marauders, and torn to pieces, and carried off in fragments. But it is not in the trees and on the ground that they find their chief prey."