6-8 boys is the officially recommended den size for our council. We don't always meet that goal, though. Last year, I had 10 tigers and it was a handful, especially when all the boys need to particptae in a discussion. Over the summer we picked up 2 more and I had to fight the assistant den leader and one commitee person (cubmaster and many parents were on my side) to break into 2 dens of 6. Luckily we did so, as we kept picking up new scouts through Nov and are now at 20 (2 dens of 10). I really didn't want 10 kids, but we can't break into 3 dens at this point (too late in the year and lack of parent leaders). We have found, though, that on certain topics (actually folding the flag, discussing state flag, etc) it is best to break our ten boys into 2 or 3 groups. I and my co-leader each take one group and the weekly parent helper takes the 3rd group if we divide into 3.