M.F.
It seems as if he is ready for a toddler bed. Does his crib convert? If it does not come with a side rail, then it would probably be best to buy a toddler bed (walmart has them for around 45.00). Our crib did not convert and we bought a rail to go under the mattress, one night he (24 months) stood up and landed flat on his face...we woke up to him crying at midnight. If you do choose to move him to a toddler bed, be prepared for that adventure too! (him getting out of bed and going to the door, playing with available toys, etc...but that is a whole other topic)