I agree with Camille and would probably use a spray bottle if I thought they understood. Since my feathers spend all day out the cage, locking away for even 5 minutes is a punishment that works for me. This is used for when they knowinly detour off the gym to chew something they should not. They even know they should not before they do it because they look to see who is watching. They do understand NO and give the wastnt me look when caught out. I make sure they understand the boundaries before I send to the cage. It is no good trying to modify behavoir untill he knows right from wrong.