What might a teacher if he/she has more than one trouble maker in the class?

if pre-plan before enter the class you may not face trouble. without pre-plan you will see to watch for ending of period.

i don't think its right to call students trouble makers. usually children try to act out due to many reasons. as a teacher you need to know hidden problems in your students life then act accordingly. 

Calling someone a trouble maker is actually a huge problem.  When someone is young and the person is regarded as a trouble maker one is creating a negative identity for the child.  It could lead to self fulling prophecies about the child and suddenly that label sticks to the child until adulthood.  It is very important to intervene early and attempt to understand why the child is behaving in a way that many consider unnaceptable. There is always a reason.  Instead of labelling the child it is important to get close to the child with a view to understanding the behaviour.  Reinforcing negative behaviour and rewarding appropriate behaviour after understanding the problem is an essential intervention.  once this happens there is no need to label young children.  Labelling is the most damaging intervention and should be avoided at all costs especially for someone who is young and can change.

It is understood that teacher has many students to face with different inborn qualities, nature and incapability, However, Teacher must be well-prepared before to get down to the level students perform, otherwise, teacher is high enough (in terms of knowledge ) to communicate well in the class and teach in a better way.