At any given time, I will have anywhere from 3 -12 teens in my house. All of my sons friends come over. It is nothing for me to go to bed knowing that one or two guys will be sleeping over to waking up and seeing 6 or 7 of them spralled out all over the house. Once we had 12 boys over....12!
Do you have an open door policy with your teens friends? I don't necessarily mean that they can come and go as they please, but do they know that they can hang out at your house and it be okay?