Ok so my year old drake named Jasper was raised inside with us for awhile and then introduced to two younger ducks about 2 weeks after is liter mate died. All 3 lived inside for about 1 month then were moved outside. I still spent a lot of time with them and to this day the two males are really friendly to humans. Jasper is getting better with new ducks, babies and strangers that enter the yard. Now heres the thing. My two male ducks do this vibrating thing with their bodies and heads when I get close to talk to them. They will come up to me and take their bill and nibble lightly on me while doing this. Going up my arm, leg, neck, getting really close to my face but never biting me hard. The whole time doing this they are doing this weird vibrating/shaking thing lol I can kneel down and they get so close its like they are hugging me. Ill try to get a video of it next time. I had a friend out there today and he was laughing. By the way Jasper used to sleep in the bed with me and watch TV