My wife and I teach CTR 5 as well and we had some problems like this at first (there are still 2 that are "extra wiggly" though) My sister gave me the best Idea...Break-up the lesson into parts.  The idea is to "shift gears" every 7 to 9 minutes.  Kids that age need change.

We usually tell one of the stories, then switch to a song or something, then back to the lesson.  We sometimes have incorporated games into the lesson.  Like Memory or 2 small basketball hoops with "right" and "wrong" on them for them to "shoot" for their answers.  We also use these if we end early until the parents come to get them.

Their favorite thing is we made them all a "primary folder" out of a 3 ring binder that we put their picture on and the keep all the projects we do in them.  We also have a "baseball card" holder page (clear with 9 pockets to hold baseball cards) that we use for small pictures we buy at the distribution center that they can pick 1 at the end of each month for being reverent and participating.

They can take them home to show parents what they did and it will all be together at the end of the year for a keepsake of the year.