So, what does it mean when they shake their necks really fast, like shivering but they are not cold? How old are they when they are full grown? How do you stop them from biting/nibbling (I don't want it to progress)? If they are going to become aggressive, are there signs? and at what age does this start? Is there any way to get them to live at the pond instead of at my house? They won't even walk down to the pond unless I take them. This is my first time for geese and I love ya'll's expertise. Thank you!! jennifer