If you are uncomfortable with really young guests, state a lower age limit in your house rules. I've seen hosts say they don't want anyone under 25, for example. If they break your house rules by booking regardless, you can cancel without penalty.
I was able to cancel, without a penalty, a group of young people who were really tardy responding to my messages. I had to verify a first and then a second thing and the first time didn't get a reponse for days. When the second question went ignored for over 48 hours, and this was after I mentioned that I needed faster replies, I called Air and they agreed to cancel it for me. I said I was uncomfortable with their behaviour (an acceptable reason to cancel apparently).
But put a lower age limit in your house rules if you are afraid of getting a group of partiers. Also, you can limit the number of young people by charging for guest over 4, let's say, but agreeing to waive the fee if that extra person is a child. I did this to discourage partiers while making it clear to families that they would be welcome.