What could cause sudden aggressive hen behavior?

[jdellosso]

Thanks Barn Goddess...you may very well be right, they do need to work it out. It's just so unusual that everything has been fine until now. They never really fought, the bigger hen just assumed she was the Queen, and the biggest tiff they have ever had was when she would shoo the other away from scratch. BB would just pick from the edges and keep her distance until she was given the ok. I agree, I can't watch them fight. Now I've put some temporary fencing up dividing their living area in half and they seem to be calmer. Being human is the big influencing factor here...Vivienne runs to me and just keeps rubbing up against my legs, looking up to me to protect her, and I feel it is my duty. How could I betray that trust and those beady, hazel-gray eyes? Oh brother, I admit it. I love my chickens!

Think I'll give them three days of solitary, then let them work it out. Yep, that's the plan. Thanks!

 

[jblum]

I am going through the same thing with my hens! I have two Rhode Island reds, got them as chicks and have had them for two years. The larger chicken (who was the more docile) out of the blue, started to beat the crap out of the smaller (but more aggressive toward the dog, cats..etc). Brownie (the larger one) started by pecking Ken off the top of the coop at night, so Ken found comfort roosting on the BBQ (great huh?) but we didn't want Ken to get hurt, so we went with it for a few weeks. However, 2 days ago Ken wouldn't come out of the coop and peck around the yard, and was acting really strange, so I pulled her out and seen that she had a large amount of feathers pulled out of her back and pink irritated tissue was exposed! At first I thought the dog may have gotten frisky, so I scolded the dog!
I put her down on the lawn and right away Brownie ran to Ken and did this weird turny dance and then bit the hell out of Ken! Ken cried out but just stood there so Brownie did it again! I then realized it was Brownie, not the poor dog! I had to go to work, so I locked Brownie in the coop and let Ken free range for that day. When my husband got home, he let Brownie out and she immediately ran and bit Ken, so my husband scolded her (no, no, tried to pick her up and move her away) and Brownie pecked my husband! Today I went out and found Ken again hiding in the coop as Brownie enjoyed ranging in the yard, its like she is prisoner. I feel awful and can clearly see that Ken is depressed and scared.
Brownie has always been the more friendly towards humans and would rather be held and pet all day than free range whereas Ken would rather be left alone, and if you separated them in the past, they would cry out to each other, absolutely inseparable! We are not liking this new behavior, but dearly love our girls (we have a 9 year old girl that carries these chickens around all weekend). I don't want "soup" (but that is funny), I just want things to back back to normal.

 

[Den in Penn]

I am going through the same thing with my hens! I have two Rhode Island reds, got them as chicks and have had them for two years. The larger chicken (who was the more docile) out of the blue, started to beat the crap out of the smaller (but more aggressive toward the dog, cats..etc). Brownie (the larger one) started by pecking Ken off the top of the coop at night, so Ken found comfort roosting on the BBQ (great huh?) but we didn't want Ken to get hurt, so we went with it for a few weeks. However, 2 days ago Ken wouldn't come out of the coop and peck around the yard, and was acting really strange, so I pulled her out and seen that she had a large amount of feathers pulled out of her back and pink irritated tissue was exposed! At first I thought the dog may have gotten frisky, so I scolded the dog!
I put her down on the lawn and right away Brownie ran to Ken and did this weird turny dance and then bit the hell out of Ken! Ken cried out but just stood there so Brownie did it again! I then realized it was Brownie, not the poor dog! I had to go to work, so I locked Brownie in the coop and let Ken free range for that day. When my husband got home, he let Brownie out and she immediately ran and bit Ken, so my husband scolded her (no, no, tried to pick her up and move her away) and Brownie pecked my husband! Today I went out and found Ken again hiding in the coop as Brownie enjoyed ranging in the yard, its like she is prisoner. I feel awful and can clearly see that Ken is depressed and scared.
Brownie has always been the more friendly towards humans and would rather be held and pet all day than free range whereas Ken would rather be left alone, and if you separated them in the past, they would cry out to each other, absolutely inseparable! We are not liking this new behavior, but dearly love our girls (we have a 9 year old girl that carries these chickens around all weekend). I don't want "soup" (but that is funny), I just want things to back back to normal.

Welsomd to BYC>

How long have you had them and how old are they? It sounds as if Brownie is a rooster.

 

[Eggin 'Em On]

We went through this sudden agression late this summer. Two weeks of awful sudden aggression to where the victim's former best friend turned absolute bully that I feared would kill her. The other two former pacifists would go along along with whatever bully was doing. After MANY hours of watching & pondering, I tried separating, anti-peck potions, holding bully to the ground, nothing worked. What seemed to finally work was observing that the bully was getting herself all worked up-- over what, I never did figure out. But when she got crazy anxious I started picking her up and quietly cuddled her for a few minutes...when I put her down quietly, she seemed much better and minded her own business around the others. Did this for a couple of days and POOF! - the peaceable kingdom was back. Now, I will say that two weeks later she went into her first real molt, so maybe that had something to do with the crazies. Hope this doesn't happen every year at molt time! Chickens....baGOK!