Nearly everything an animal does is the result of an inborn instinct acted upon by an outward stimulus. The margin wherein intelligent choice plays a part is very small. But it does at times play a part--perceptive intelligence, but not rational intelligence. The insects do many things that look like intelligence, yet how these things differ from human intelligence may be seen in the case of one of our solitary wasps,--the mud-dauber,--which sometimes builds its cell with great labor, then seals it up without laying its egg and storing it with the accustomed spiders. Intelligence never makes that kind of a mistake, but instinct does. Instinct acts more in the invariable way of a machine. Certain of the solitary wasps bring their game--spider, or bug, or grasshopper--and place it just at the entrance of their hole, and then go into their den apparently to see that all is right before they carry it in. Fabre, the French naturalist, experimented with one of these wasps, as follows: While the wasp was in its den he moved its grasshopper a few inches away. The wasp came out, brought it to the opening as before, and went within a second time; again the game was removed, again the wasp came out and brought it back and entered her nest as before. This little comedy was repeated over and over; each time the wasp felt compelled to enter her hole before dragging in the grasshopper. She was like a machine that would work that way and no other. Step must follow step in just such order. Any interruption of the regular method and she must begin over again. This is instinct, and the incident shows how widely it differs from conscious intelligence. If you have a tame chipmunk, turn him loose in an empty room and give him some nuts. Finding no place to hide them, he will doubtless carry them into a corner and pretend to cover them up. You will see his paws move quickly about them for an instant as if in the act of pulling leaves or mould over them. His machine, too, must work in that way. After the nuts have been laid down, the next thing in order is to cover them, and he makes the motions all in due form. Intelligence would have omitted this useless act. A canary-bird in its cage will go through all the motions of taking a bath in front of the cup that holds its drinking-water when it can only dip its bill into the liquid. The sight or touch of the water excites it and sets it going, and with now and then a drop thrown from its beak it will keep up the flirting and fluttering motion of its tail and wings precisely as if taking a real instead of an imaginary bath.