What was the relationship between Bud and Bugs?

Bud and Bugs are friends. They are also travel partners for a short time.  
Bud explains that he and Bugs met when they were both staying at the Home together. Bud tells his readers a great little story that explains why people call Bugs "Bugs." It's because a cockroach once got stuck in his ear.
After Bud enacts his vengeance against Todd Amos and escapes from the Amos household, he decides to go out "on the lam." In chapter 8, Bud is reunited with Bugs. The two agree to team up and head out west together by illegally riding on the trains. On their way to the train yard, the two boys spend some time in a Hooverville shantytown and meet Deza Malone. Bud gets his first kiss, and then the two boys prepare to catch the train. As the train is leaving, Bugs manages to get himself on it, but Bud is unable to catch the moving train. Bud is then forced to consider the option of walking to Grand Rapids.