The Den Meeting has started and all of the sudden the boys are bouncing off the wall and seem to out in front of everything. Maybe your first reaction is to panic and head for the door, your second reaction is to start raising your voice and try to get control again, both are understandable. How would I handle it, I will answer this from the view point as a new leader and experienced den leader and also a father of an ADHD Cub Scout.
New Leader Prospective: When I was about to start I had the Cubmaster helping me with the first 2 Tiger Den meetings. This really helped me understand how to run the meeting, how to keep control and keep it fun for the boys. Now I have 8 boys in my Den and we meet in the evening, so they already come a little hyper. First, remember to train the boys when the scout sign goes up it is time for them to quiet done and use their sign. There will times when the boys will take a minute to respond, be patient, be silent and do not say "Signs UP". Train the boys they need to respond and quiet down. After I do this with my Den, I remind them that we only have an hour for the meeting and the more time I have to keep "using the Scout sign" the less time for the fun stuff we have coming up. This will really get their attention and usually settles them down.
Remember your other resources! Get training and use your parents. Also remember how you do your programming for Den meetings. I have learned that keeping the different parts of the meeting 5 to 10 minutes chucks keeps it moving and the boys attention. I also play one or two games at the end of my den meeting so they have a fun activity to look forward to and if they don't behave they run out of time to play the games.
Experienced Leader Prospective: All of the above still applies. Try to get another Den Leader to help you, I found out after my Tiger Den Leader year I couldn't do it all myself and recruited another father to become the other Den Leader. Also attend other training offered if possible such as PowWow's, they show you other things you can do with the boys.
You can count on meetings or parts of your meeting getting out of control. Remember, stay calm and quiet, use your Scout sign and wait quietly for the boys to respond. First time this happens, it will seem like forever until you hear silence. If you panic or start yelling the boys will sense it and it could take longer to get control back.
Father of ADHD Cub Scout Perspective: I have 2 sons in Cub Scouts. When we met both are as hyper as the other boys, but I do keep an eye out for my ADHD son to make sure he is doing ok. Mom also comes to all meetings and helps my son if he needs it, but most of the time he is doing well on his own. I have also done much training and research on working with special needs scouts which has given me a better understanding of how to best work with them.
I hope this helps and remember have fun with the boys.