But "watching" all day long will do no good with turtle-doves. Whether building or not, they never tell you, and when they catch sight of you they fly off at once, as if they did not care where they flew to, or whether they ever came back there again. Let them go, but come back yourself later on to the same spot, approaching it, however, from the opposite direction. And if you flush them again, you may be sure that their nest will be, or is, thereabouts: midway, probably, between the two points of your approach. In a few days go back to find the nest, and if you walk backwards and forwards in the undergrowth, keeping your eyes upwards, so as to look through the bushes from underneath, you will find it, if it is there. For the hen-bird sits very close, and goes off her nest with a flap of the wings that is unmistakeable. Apart from this, if the bird is not at home, you may often find the nest by seeing the white eggs in it from underneath, the yolks of them showing against the sky a delicious pinky yellow. For the nest is a mere ghost of a nest--a skeleton--and can easily be imitated by taking a handful of thin birch and hazel twigs and sprinkling them at all angles in a heap. Such a nest a pair of birds may easily build in half an hour, and this, perhaps, is one reason why they are never seen at work. Why they should be content with such a skeleton of a nest or how so frail a network bears two bulky nestlings and their mother, is a mystery. But as Prior sings: "Each according to her kind Proper material for her nest can find, And build a frame which deepest thought in man Would or amend or imitate in vain." When they are on the wing, turtle-doves seem to like to keep below the level of the tree tops, and seldom, therefore, [Illustration: THE NUTHATCH AT HOME] come into sight conspicuously. But I have sate in an orchard and watched them, several together, flying about among the apple-trees, and feeding on the ground, when they were unconscious of my presence. Their flight is singularly beautiful and interesting, for the obstructions they meet with compel them to make the most graceful and sudden evolutions to avoid collision. And I remember very well, how, as I sate there, looking up from my work every now and again at the wing-clapping and testily-cooing strangers, sporting and squabbling by turns, I heard, what I had never heard in that garden before--the tapping of a nuthatch. "_Nuthatch piercing with strong bill._" SOUTHEY. "_Rap-rap, rap-rap, I hear thy knocking bill._" MONTGOMERY.