found beer in my 13 year olds room

yesterday I went in my son's room to grab his clothes hamper and I noticed a bottle sticking out from under his bed. I reached down to see what it is and I pulled out a bud light bottle I looked underneath his bed and I found a whole box of them. the other night he had a couple of his friends over so I'm thinking that's where it came from. I'm a single parent and his dad is not present in his life. what do I do? do I talk to the other parents about this?