Awhile back I had a 22 month old boy start with me.... He would climb out the the playpen as well and start playing with my sons stuff ... So here's what I did and it worked ..... When I put him in bed I said with a stern voice and mean face "no climbing out" then I shut the door and listened and as soon as I heard he feet hit the floor I swung the door open and swooped in picked him up and put him back in bed and said " I said no climbing out" , again I shut the door and waited till he did it again. After a week he never climbed out. I have all my daycare kids sleeping in separate bedrooms with fabs running so there is no chance of them bothering anyone else . I also put this particular child down last during this phase so I was able to stand outside the door for as long as needed. Is there any way you can separate these kids so they sleep alone. I have a play pen in each one of my bedrooms.
For the boy I would just ignore him and not give in to his crying and tell him to ho play or maybe put him in his high chair with a few toys or in a play yard with toys out of the way maybe he is feeling overwhelmed by the activity level ..... Is he full time?