(It can also be used to describe the husk on maize, and as a verb, to shuck, to shell an oyster.
However, it is also an old English word believed describe a demon, or from East Anglian dialect meaning ‘shaggy’.
And "Aww shucks" is an expression of regret or embarrassment. I wonder if rats say that? (You will need to check an earlier IF to understand this.))