Why Narrator Asked Must You Work So Hard

Question - The narrator asks the boys," Must you work so hard? You both look rather tired." The boys reply,"We are not complaining,sir." What do you learn about the boys from their reply? 

Answer: From their reply we can make out that the boys were highly commited and devoted towards work at such a tender age.They had extreme patience, endurance and tolerence. 

They were also extremely hard-working.They were  non-complaining,

rough and tough children who wanted to maintain their dignity and self-respect.