Pre-K Group Chess Lessons

I have taught chess at every level from K-1 to High School. Each level, as a group presents
quite often different challenges. Have any of you worked with an exclusive Pre-K group??
I have taught, very successfully, the exceptional from this age group on an individual, or
small group basis. But, as a larger group, no. I am wondering–how viable of an idea is this, and also, what approaches would you recommend different from that in teaching the
K-1 group??? I appreciate whatever ideas you may have here.

Rob Jones