Ants are the most intelligent of all insects. We learnt a little about the home of the Hill-ant in Book I., to which you can look back for drawings of the male, female, and worker ants with their grubs and cocoons.
Now we will look at some other ants, and learn about their ways. There are two very common kinds to be found in most gardens. One is red and the other black. They both build their homes underground, by clearing out the earth with their jaws and feet, and so making galleries and chambers. There is generally a little rise in the ground, where they are at work, making a dome above the nest, but it is not so conspicuous as the hill of the Hill-ant. If you dig a deep hole on one side of a nest you will open the chambers and see the grubs inside them, and, if you do not make it too big, the busy ants will soon put it right again.
Then you will take a few cocoons, and put them in a little earth under a glass so as to see the young ants come out. But do not take the grubs, unless you take some grown-up ants with them, for they cannot feed themselves.
If you get a black and a red ant you will know them apart, not only by their colour, but because the black ant has one round knob (1, p. 75) in the thin part joining her hind body to her fore body, while the red ant has two knobs (2, p. 75). By this we know that the red ant has a sting, and the black ant has none. All English ants which have two knobs to their abdomen can sting; but those with only one knob cannot (with one rare exception). These which have no sting attack their enemy with their strong jaws, and squirt out a strong acid over them.
There is a little yellow ant which lives in our houses and eats our food. She has two knobs, and stings quite sharply. I once cut open a cake which had been some days in the cupboard and found the middle full of these ants. They swarmed on my hand and made it tingle with their stings. This ant generally makes her home behind the fireplace.
If you put your ants under a glass, and give them a piece of nut or bread to eat, you may see them use their outer jaws to scrape the surface, and their tiny tongue to lick off the juice or oil, while they pass the food to the inner jaws, just as the bees and wasps did. You may also see them pause to stroke their body with their front legs. Look closely at these and you will see a small spur on a joint a little way up the leg. This spur has more than fifty fine teeth on it, and there are some coarse teeth on the leg itself. These are the ant's brush and comb. She scrapes herself with them, and then draws them through her outer jaws, or mandibles, to clean them.
She has very small eyes, and always uses her antennæ to find out anything she wants to know. These stand out in front of her curious flat head, and are very mysterious instruments. When ants want to talk to one another they touch their antennæ, and in some strange way they can tell each other where to go and what to do.
The Garden-ants live much more underground than the Hill-ants, but you may often see them sunning themselves in the garden, or cutting off blades of grass with their mandibles to line their nests, or tearing a spider or fly to pieces. They often seem to run hither and thither as if they did not know what they were doing, but if you watch you will find that each one has an object. Some are carrying things into the nest, others are climbing the stalks of the flowers to sip their honey. As these honey-laden ants go home, if they meet with an ant which has been doing other work and is hungry, the well-fed ant will squeeze honey out of her throat to feed her friend. For it seems to be a rule among ants that each one helps the other.
And now you must watch day by day till you see a much more wonderful thing. You will remember that we saw in the first lesson little plant-lice called Aphides sucking juice out of the stalks of plants. But we did not notice that they have two little horns at the end of their bodies. As they suck and suck they become too full, and the sweet juice often oozes out of these horns. You may see it standing in tiny drops on their tips.
This juice is just what the ant loves, and you may be fortunate enough to see the garden-ant take it, because she brings the aphides and puts them on daisies near her nest. She goes up behind the aphis and strokes its sides with her antennæ, so that it gives out a drop of honey from its horns.
She has another herd of these honey-cows safely hidden underground where you cannot see them. She carries them down into her galleries, and puts them on the roots of plants. There she takes care of them, just as she does of her own grubs, and keeps their eggs and young ones through the winter, ready for the next spring. In our climate ants sleep through the winter, but in warmer countries they remain awake and store up food.
When you are digging into the nest of a Garden-ant look very carefully at the roots you dig up, and you will most likely see some plant-lice on them. If you put them carefully back they will be none the worse, and the little ant will not have lost her honey-cows.
There is a small yellow ant called the Meadow-ant, which lives in great numbers on heaths and meadows, and has no sting. She keeps nearly all her honey-cows underground, putting them on the roots of the grass. Sometimes when you are ploughing up a field you may cut through one of these nests. If you do, stop a minute and watch the ants. Their first care will be for the ant-grubs and cocoons. But as soon as these are carried down you will see them fetching the little green plant-lice as carefully as if they were their own children.
The Hill-ants do not bring their cows home. They visit them on the plants, and many battles between the ants of two nests begin because one colony has interfered with the other's cows. Then the working ants turn out of both nests and fall upon each other two and two, biting with their mandibles and standing on their hind legs, each trying to squirt formic acid over its enemy. These battles often go on for some days till one party is exhausted.
The battles are fought, and the honey-cows are milked, by the working ants, of which there may be thousands in a large nest. The queen-ants do no work, beyond laying the eggs. There may be two or three queen-ants in a large nest, and they never quarrel like queen-bees. When they are laying eggs in the home they have no wings. But in the summer there will be a number of winged male and female ants growing up in the nest, and some warm day they fly out, and you may see them rising and falling in the air like gnats. Then they tumble helplessly to the ground and crawl about. The males are eaten by birds or die. None of them go back to the nest. Those of the females which are not killed have their wings pulled off by the workers, or pull them off themselves, and they go back to lay eggs, or join a new nest.
Find any ants you can. Keep them a little, feeding them with honey and giving them some earth to build. Keep a few aphides on a plant to see the honey-drops. Examine an ant's nest by opening the side; put the aphides and cocoons back carefully.