what game is tom playing with Joe harper ?

Tom is restless and school and amuses himself by playing with the tick Huckleberry traded him. After a short time, Tom and "bosom friend" Joe Harper begin to fight over who is allowed to play with the tick, disrupting the classroom with a fistfight and attracting the attention of the schoolmaster. This is right from the GradeSaver Site! Take a look in the source link below.

It is mainly a game of distraction so that they can focus on other things.