The main reason is to let them settle in to thier new enclosure and give them time to destress from the move they just made. Then you need to hold them breifly at first 10-20 min and work your way up in time. This will make for a much better adjusted snake who is secure in thier new enviroment. Remember baby snakes are usually food for other animals if they do not feel secure you can run into problems with eating and health due to stress