I have moved all 3 boys pretty close to them turning two.

DS#1 - 1 month before he turned two cause we were going on a holiday and there wasnt a cot for him.
DS#2 and DS#3 - a week after they turned two.

DS#3 hadnt ever tried to climb out of his cot, we just thought we would do the same as we have for the others.

Have had a bed guard for all of them.