Robinson Crusoe, narrated in the first person, is dominated by the title character. The other major character, Friday, appears after two-thirds of the narrative has been told.
Crusoe is adventurous by nature. Against his father’s “serious and excellent counsel,” Crusoe embarks on the seafaring career that he feels will satisfy his “wandering inclination.” Even late in life, after his return to England, where he marries and has three children and is later widowed, Crusoe once again heads out to sea for another long voyage that takes him to China.
Robinson Crusoe’s character is a study in contradictions. He is by turns an ardent capitalist and an introspective Christian; a wanderer attracted to adventure and a civilized Englishman who creates a cozy dwelling for himself; a believer in the dignity of the human being and a slave trader. Defoe portrays these contradictions as typical characteristics of a middle-class English Protestant tradesman of the period.
By contrast, Friday, a native of an island close to Crusoe’s, is depicted as a savage-a reformed cannibal. Crusoe sees Friday as his “faithful, loving, sincere servant”; in fact, the first English word Crusoe teaches Friday to say is “Master.”
Many of the important themes in Robinson Crusoe are embodied in the title character and in his interaction with Friday. Through the story of Crusoe’s sojourn on the island, Defoe comments at length on several social and philosophical concepts. The novel is an allegory for a progression from spiritual alienation to salvation in that Crusoe’s life moves from rebellion to punishment to conversion and finally to deliverance. But Robinson Crusoe is also an economic document, with its focus on the taming of a wild environment, its portrayal of Crusoe as a man who keeps a careful record of his projects and crops, and its depiction of the colonial impulse in Crusoe’s education of Friday. Furthermore, Crusoe’s journal contains several passages in which he reflects on time and labor and the acquisition of material possessions.
Woodpeckers make their nests and food stores by pecking holes in trees. The speed at which a woodpecker bores into a tree with its bill is approximately 40 km/hour (25 miles/hour). This, in fact, is an extraordinary speed that could have damaged the woodpecker. However, there is a special locking system in the bird's beak so that it does not sustain injury. If this special system did not exist, the woodpecker's beak would crack in two because of the high speed. Besides, if the impact of the stroke went directly to the brain, then the bird would lose consciousness. Yet, such a thing never happens since Allah created the bird together with what it needs. The woodpecker's brain is placed at the same level as its beak. Muscles on the lower part of the beak act like "shock absorbers" and reduce the shock that occurs while boring into the tree. 
What we have mentioned so far are only a few of the general characteristics of woodpeckers. Apart from those mentioned, every woodpecker species has many characteristics peculiar to itself. Now let's consider a kind of woodpecker that hides acorns in trees.
Throughout summer, the acorn woodpecker bores "holes" in a dead tree trunk because at the end of the summer it will fill these holes with acorns, on which it will feed during winter. Acting like a hammer, it drives one acorn in each hole. This takes a great deal of the woodpecker's time because it tries to find the acorn that fits exactly into the hole it has bored. If the hole is big and the acorn is small, then the loose acorn will easily be taken by other birds. If the hole is smaller than the acorn, then the acorn will be damaged while it is being forced into the hole. Therefore, it takes some time for the woodpecker to place acorns by trial and error. 
