What details at the beginning of the text reveal the kid as a handful?

From the very first introduction of the boy, it is quite clear that he is bad news—he is throwing stones at a kitten. When Bill offers him a bag of candy, the boy throws a piece of brick at him and hits him in the eye. When the Bill and Sam go to grab the boy and kidnap him for a ransom, he puts up a fight that is described as being like that of a giant bear.
Once the men have gotten the boy back to the cave they have fashioned into a campsite, he kicks Bill in the shins, causing multiple bruises. After this, when he seems to grow more comfortable with his kidnappers, he begins to talk and ask questions about all sorts of random things. He ends up keeping the kidnappers awake with his rambling for three hours after the men have made their beds and prepared to go to sleep.
The following morning, the boy tries to scalp Bill with a knife. Things only continue to get worse from there.