the biggest problem is learning them the way back in. A cage is the simplest way over the sputniks and put them out in the cage keep them hungry they will soon trap then simply remove the cage but keep them hungry as they alresdy know the way in job done . another way is the week of separation put two or three at a time on the landing board but stay beside them ,eventually they will trap fear of the sputnik is gone you will find this invaluable later on you only need to do the second one once it also gives them an early look at their surroundings