My ducks started biting around 3 weeks old. I remember the first time Choco bit me I was feeding him mealworms and he accidentally bit my finger then immediately backed away like he knew he did something wrong. Now that they are older, theyre not just biting me by accident anymore. When I try to give them a fresh worm from my garden they will bite every place on my hand except where the worm is...No way their beak-eye coordination is that bad! Lol They also bite my hands when I open their coop or refill their water, bite at my feet and ankles, peck at my legs, and one got on my lap and bit me on the face. The bites vary in degree. Sometimes its just a little nibble that tickles, and sometimes it's hard enough to be unpleasant but doesn't necessarily hurt. Is this just their way of communicating or showing affection kind of like how a dog licks? EDIT: I hand raised them from 2 days old. They eat out of my hand and occasionally let me pet them, so I'm pretty sure theyre not biting because they hate me and I dont sense any aggression. Just curious why they bite and if it's normal.