Maybe his age is too old for the crib? by the age of two I transition the children to the floor mats. When they get up they are informed to quietly come out not disturbing the others. you cant make him nap as long as others, if he only needs a short nap, allow him to get up and look at a book or watch a quick show. (at that age, I have really cute alphabet, color, and shape videos the children watch) maybe you could play that if your busy, or read him a book and bond with him while the others are sleeping. My rule of thumb is: if they can CLIMB out of a crib...they are too big for a crib.