3.1 Feather, Beaks, Wool, and HairSince very early days, humans are very fascinated with understanding the concept of how birds can fly, and how birds (like duck) can protect their wings during swimming or rainy condition. You have been already noticed that the bird’s wing does not get sloppy, easily during rain or rainy season. So, this is mainly considered keratin(β-form) protein may involve for providing mechanical support to the feather, and thereby prevents feather to get sloppy. To further understand this concept, Filshie and Gogers (1962) analyze feather under transmission electron micrographs, and their study reveals the filament-matrix structure with the β-keratin filaments. This structure was about 3 nm in diameter and embedded in an amorphous matrix. The keratinous material is also present in rhamphotheca (outer surface layer) of bird beaks, and it allows the beaks to participate in a variety of functions, like feeding, social interactions, fighting, and grooming (Luester 2006). Usually, bird beaks fall into two categories: (1) long thin and (2) short/thick except in toucan beak, as it is both thick and long (Wang et al. 2016b). Wool and hair is the remarkable example of the hard-keratinous material. Wool is the excellent animal fiber, containing 82% keratinous protein. It is widely used in textile application and is scientifically important because of its mechanical and structural behavior (Feughelman 1997).Hair is another widely used and studied fiber. Study on hair and wool revels that they both have common features except wool has large diameter. In many cases, hair plays an important role in terms of protection against dust and pathogens (hairs in nostril).