If you are teaching to very young learners, you have to find several different ways to communicate with them. One of the best ways is using puppets especially with the ones you are having problems.The idea may sound ancient to you but when it is very young learners, puppets are brand new for them (like most other things!)  and a very simple and effective way to build a bridge between. There are some different ways to use puppets:

• Reflective Listening: You talk with the kid through the puppet. The child will know that s/he is heard by the adult/teacher but will still talk, ask and answer questions  to the puppet. Talking through a puppet will provide a safer psychological  environment for the child so it will be easier to talk about the problems you are  or the kid is having. Here you can use animal puppets (especially animal family puppets) which have paws so that the child can express  even the violent feelings.
• Another way is whispering. This technique is especially good for the shy ones. Here, you let the puppet talk both to you and to the child. The important thing here is to make the puppet whisper something to you that the kid will not hear and will be curious about what is going on between you and the puppet. After a few days the child will start asking questions and will also start a communication with the puppet and you. 
• Active reflection: What ever the child says you repeat / report it back to you . It is better to give an example I guess;

-Child: I was sitting there.

-Puppet: He was sitting….

-Child: And then Ella came  and sat next to me.

Puppet: Ella sat next to him…

-Child: Then she pulled my hair.

-Puppet: Ella pulled his hair…

After reflecting/reporting the student’s words, you should explore his/her feeling(s) and say it through the puppet. So the example may continue like;

-Puppet: Oh! You are angry with Ella!

When you are using puppets it is a lot better if you change your voice and keep the energy level of the child and the puppet the same. If the child is bashful or silent; an excited puppet will not surely be a good idea!