Its body is usually covered with a substance much resembling a shawl , sometimes red , sometimes blue , often plaid , and , strange to say , they frequently change skins with one another . On their heads they have a horn very like a stiff brown paper lamp-lighter . Wings of the same substance flap upon their shoulders when they fly ; this is never very far from the ground , as they usually fall with violence if they attempt any lofty flights . They browse over the earth , but can sit up and eat like the squirrel . Their favorite nourishment is the seed-cake ; apples also are freely taken , and sometimes raw carrots are nibbled when food is scarce . They live in dens , where they have a sort of nest , much like a clothes-basket , in which the little Brops play till their wings are grown . These singular animals quarrel at times , and it is on these occasions that they burst into human speech , call each other names , cry , scold , and sometimes tear off horns and skin , declaring fiercely that they `` wo n't play . '' The few privileged persons who have studied them are inclined to think them a remarkable mixture of the monkey , the sphinx , the roc , and the queer creatures seen by the famous Peter Wilkins . This game was a great favorite , and the younger children beguiled many a rainy afternoon flapping or creeping about the nursery , acting like little bedlamites and being as merry as little grigs . To be sure , it was rather hard upon clothes , particularly trouser-knees , and jacket-elbows ; but Mrs. Bhaer only said , as she patched and darned , `` We do things just as foolish , and not half so harmless . If I could get as much happiness out of it as the little dears do , I 'd be a Brop myself . '' Nat 's favorite amusements were working in his garden , and sitting in the willow-tree with his violin , for that green nest was a fairy world to him , and there he loved to perch , making music like a happy bird . The lads called him `` Old Chirper , '' because he was always humming , whistling , or fiddling , and they often stopped a minute in their work or play to listen to the soft tones of the violin , which seemed to lead a little orchestra of summer sounds . The birds appeared to regard him as one of themselves , and fearlessly sat on the fence or lit among the boughs to watch him with their quick bright eyes . The robins in the apple-tree near by evidently considered him a friend , for the father bird hunted insects close beside him , and the little mother brooded as confidingly over her blue eggs as if the boy was only a new sort of blackbird who cheered her patient watch with his song . The brown brook babbled and sparkled below him , the bees haunted the clover fields on either side , friendly faces peeped at him as they passed , the old house stretched its wide wings hospitably toward him , and with a blessed sense of rest and love and happiness , Nat dreamed for hours in this nook , unconscious what healthful miracles were being wrought upon him . One listener he had who never tired , and to whom he was more than a mere schoolmate . Poor Billy 's chief delight was to lie beside the brook , watching leaves and bits of foam dance by , listening dreamily to the music in the willow-tree . He seemed to think Nat a sort of angel who sat aloft and sang , for a few baby memories still lingered in his mind and seemed to grow brighter at these times . Seeing the interest he took in Nat , Mr. Bhaer begged him to help them lift the cloud from the feeble brain by this gentle spell .
Glad to do any thing to show his gratitude , Nat always smiled on XXXXX when he followed him about , and let him listen undisturbed to the music which seemed to speak a language he could understand .
Billy Brops Chirper jacket-elbows minute nook roc trouser-knees violence willow-tree