Assimilation.
This is a process by which Tommy is getting all the necessary social skills and mental skills he needs to be able to adapt and adjust to life in the human society. He learns about the intricacies of his surrounding environment and everything around him. Whatever that is picked up sticks, just as his father is showing him the squirrel, next time Tommy encounters a squirrel he would be able to identify it himself without the aid of his father.