Some breeds of chickens are more aggressive than others, and all will create a pecking order. I'm not familiar with this severe of aggressoin in such young birds, but anything's possible. Perhaps the particular strain is particularly aggressive? I have a more docile variety, and have lost one adult bird to this "establishment". The others attacked her when the roo had her pinned and got to her brain by picking out her eyes. (yes, graphic, I know, but I believe an important detail). In your case, perhaps the one they killed was the weakest, and once they figure out their order, things may improve. Can you tell if the meanest ones are roos or hens? At this age, the roos will be a bit more "gangly" and have a larger comb. With the # of chickens you have, you'd want no more than one roo anyway, too hard on the hens. Even if you can't tell, or if they are hens, consider culling out the worst offenders, they may never change and be a constant problem. I'd either find them a new home or serparate them from the rest, fatten them up and eat them this fall. I'm sorry you have this problem! But sometimes you really must be pro-active! Also, consider keeping the ducks separate, unless after removing the "bad" ones settles things down. Good luck!

Thanks for the advice! I can't tell which is which yet, I usually get them when they're almost old enough to start laying. I'll look closer when I go out in a bit, but thanks for telling me how to tell. Doesn't seem like they are messing with my runner ducks. It seemed like they were all alot calmer this morning, I'm keeping my eyes on them though! I have no problem getting rid of the aggressive ones, especially if I find another chick looking like the last one... poor thing. There's an Amish family about 30 minutes from me, they always take my hens when they quit laying. I love my ducks &the chickens but I won't tolerate too aggressive birds, especially with my 2 girls out there taking care of them! On a cute side, we've been teaching them how to go up & down the run & play in the yard. Too cute! Thanks for the advice.

Thanks for the advice! I can't tell which is which yet, I usually get them when they're almost old enough to start laying. I'll look closer when I go out in a bit, but thanks for telling me how to tell. Doesn't seem like they are messing with my runner ducks. It seemed like they were all alot calmer this morning, I'm keeping my eyes on them though! I have no problem getting rid of the aggressive ones, especially if I find another chick looking like the last one... poor thing. There's an Amish family about 30 minutes from me, they always take my hens when they quit laying. I love my ducks &the chickens but I won't tolerate too aggressive birds, especially with my 2 girls out there taking care of them! On a cute side, we've been teaching them how to go up & down the run & play in the yard. Too cute! Thanks for the advice.