Ants, moreover, do their hearing thru their legs. We ourselves, do something like this, when we grip one end of a stick in our teeth and scratch the other end with a pin. Even a lead pencil will do for the experiment; the sound is twice as loud when we shut our teeth on the wood and hear the scratching thru the bones of the jaw, as it is when we listen with our ears alone. Miss Helen Keller, completely blind and deaf, managed nevertheless to enjoy music by holding a music box in her hand, and feeling the jar; and she conversed in a telegraphic alphabet by tapping with her foot on the floor, taking the reply in the same way, by the jar, when anyone answers her.
The ants manage in much the same way. Stand an ant on cotton wool, and he is totally deaf to all sound. No sound, high pitched or low, can reach him thru the air. But put him on a hard surface, on his legs, and he hears thru his legs, taking the jar much as Miss Keller does. In fact, all sound is jar, either of air or of something else; a fact which you can easily prove for yourselves by striking a bell, and then touching a finger nail to the vibrating edge. Naturally we hear best with ears; but lacking these, any part of the body will make shift that can feel jars.
XXX
Ants’ Noses
Ants see, then, and hear. But their hearing is not at all good; while they do most of their work in pitch darkness underground, where they can not possibly see anything anyway. So they depend on touch, and still more on smell. Smell, therefore, is their chief sense, as sight is ours. So much thinking as they do, they do largely with their “smell center.”
We in a strange country, find our way back home by remembering what we saw on the way out. An ant gets home by following the smell of its outward trail. We recognize our friends by sight, and know them by the way they look. An ant recognizes its friends by touching them with its feelers, as no doubt you have often seen ants do, and so getting the familiar odor, smelling out each other’s claims to acquaintance.
For the feelers or antennae are the ant’s nose. It feels with them, and it also smells. As you can discover by looking at any ant, the antenna is like some whips which have a stiff handle and a long flexible lash fastened to its end. The handle sticks out sidewise, and the lash is jointed so that it can be moved about freely.
Our common brown ant has eleven joints in its whip-lash. With the joint at the tip it smells its nest. With the tenth joint it gets the general odor of the colony to which it belongs. With the ninth, it follows the scent of its own track. With the eighth and seventh, it recognizes the helpless young which are its care. By means of the sixth and fifth, it knows its enemies, the inhabitants of other ant cities with which it is at war. What the remaining four joints next the handle are for, is by no means clear.
An ant, therefore, which has had the outermost joint of its feelers cut off, or has lost them in battle, does not know its own nest. One that has lost the two outermost, does not recognize its fellows when it meets them away from home. One that has lost the outermost three joints, can not smell its own track and so can no longer find its way home. If the seventh and eighth joints are gone, the ant no longer has the slightest interest in the eggs and the helpless young, which before the mutilation it would have fought to the death to defend. Apparently, it no longer knows what they are; like the men who wake up some morning with a little blood clot on the surface of their brains over their left ears, who can see words but not read them, and don’t know what their wives and children are. On the other hand, ants from different nests, which have lost the whole of their antennae down to the fourth joint, live together in perfect peace and harmony. But ants from different nests, deprived of their antennae only as far as the sixth joint, straightway start to fighting like cats and dogs; and never leave off till they are all killed or disabled.
Apparently then, the ant has enemy-smelling spots, and egg-smelling spots, and track-smelling spots, and friend-smelling spots, and nest-smelling spots, strung along in order on the lash-like part of its feelers; so that when one of these sets of spots goes, that particular sort of smell goes with it.