Struggle with Authority

Language Arts has been a struggle this week.  We are doing Lit Groups with the book The Rats of NIHM. For Lit Groups some students switch classes based on reading ability.  I have the middle reading group.  For our class we split students  into two different literature circles and my cooperating teacher and I each take a group daily.  However, regardless of which group I am in, the students are much more off task and noisy than when working with my co-op.  I know that this is somewhat normal because I am not 100% viewed as a teacher with these students, but I am not sure how to proceed at this point.  One group is much worse than the other, and it is always particular students, but I don’t know if I should be separating students or assigning seats, or to just keep at it and little by little it’ll get better.  Additionally, there are always students (always boys) who do not write things down on their papers.  When approached about this they say they already knew that, or it wasn’t interesting or surprising to them.  I am working on getting the students to see me as another teacher and treat me like they would my co-op.  I think with time it will all work out  but it’s just something I have been thinking about this week.