Okay, so I've had my chickens for about four years now. Three died from attacks by my rabbit this winter. First, a little bit of background: I have a spayed female rabbit who weighs around 1.5 - 2 kg. I don't put her in a hutch all day (the hutch wasn't a small one, either, and had a large runway and shelter), and I give her time to roam free around my garden (and even into my house sometimes) throughout the day. She's always been quite calm and docile, and she isn't destructive. I don't think she's ever bitten or scratched me, and she hasn't scratched any furniture prior to the incident. Her previous owner told me before that she never had any problems with other pets, and likely wouldn't attack them. Her hutch is nearby the coops of my chickens, which used to host (of course) ten chickens. There were two Orpingtons, a welsummer, and three leghorns, two Rhode Island Reds, a Welsummer, and a Cornish. I now have a sole male Rhode Island Red with three other hens (the Welsummer, other Rhode Island Red and the Cornish), but the three leghorns consisted of two males and one hen, the previous welsummer was also a female, one of the Orpingtons was a female and the other male. The rabbit did interact with the chickens, who would also roam outside (didn't let them out all at once), but they never really interfered with each other too much. Before this incident, the most that I saw out of them was the rabbit driving an Orpington off a plate of food. Otherwise, they seemed fine with one another. But one day, I noticed that the rabbit had been acting stranger than usual. She would twitch and start scratching and biting the wood of her hutch. I came out to see if there was anything wrong, and I let her into the house for a while. But then I also saw that she wanted to go outside desperately the day I let her in, even though the area was covered in snow. The coops of the chickens were large and had enough shelter for them to survive the cold (they did so before). The rabbit would start ramming at the door to my garden, and started scratching it as well. Seeing that she was a bit stressed out, I let her back into the hutch again. I observed her very carefully, just to see if things would be different this time. It wasn't. In fact, she started scratching even more, both when she was inside and outside. Then, I noticed that there was a hole underneath the hutch, as if she were trying to dig somewhere. I managed to cover it up, but she was still very persistent, and would continue to dig, scratch and run all around the place that same week. I didn't really know what to do by this point, and I put her in and out of my house each few days. About a few weeks after I noticed the hole in the hutch (I managed to stop her from digging under her hutch from the week after it happened), there were scratch marks on the wood of the coop, and holes that were dug to the other side. I went into the coop to see that two of my chickens were injured, and they had scratch and bite marks all around them. This wasn't the work of a fox, cat, hawk or other competent predator, who would go for a quick kill... this was more sinister. The wings and legs were bitten, and feathers were also torn off. Three of them (the male Orpington, the male leghorn and the welsummer) were actually dead. The bodies were still in the coops, but it appeared that certain parts were just missing (e.g. wings, legs, feathers, even some heads). They were literally torn apart; their faces and necks had been mangled up, and parts of the wings and chest had been ripped up too. Most of the bites seemed to be on their body, though. There were also bruises on some of the chickens, suggesting that a fight might have happened before they were dispatched (also evidenced by the scratching and maybe the biting?). Rabbits can headbutt and collide. My first thought was that it might have been my cat, but I thought the signs of the scratching and digging were all too familiar. I went back to the hutch to see a little bit of parts of the chickens there, and... my rabbit eating them. My rabbit appeared to be completely unharmed, and I was surprised by how it seemed as if none of the other chickens had noticed my rabbit in the process of killing some of them. It was a horrifying sight, but I decided not to sell the rabbit immediately, and I'm keeping it indoors at almost all times, away from proximity of the coop. She suddenly seems quite fine now, as if nothing had happened, but I fear that she might turn violent again at some point. Why did my rabbit do this? What should I do now? Has anyone else experienced a similar problem to this one? EDIT: People have often brought up predators. 1) No raccoons where I live. 2) A weasel, stoat, marten or mink would have probably gone after the rabbit first. 3) I had a wire to keep foxes and dogs from digging in, not rabbits. 4) I've done everything I could previously to prevent rats by warding off mice, cleaning up refuse, debris and meals, removing water sources at night, securely covering feeders, having my feed in both an airtight container and treadle feeder. 5) I've looked for signs of predators before and after the incident, and I didn't find anything to suggest that there was a predator around that would threaten a chicken, other than the rabbit. No nests, no dens nearby, etc. I inspected carefully throughout the days for predators in and outside my yard. 6) The method of killing appeared to be messy and not reminiscent of an experienced predator. A cat, fox, hawk, owl, snake or weasel wouldn't have bitten all over a chicken, or have rammed or scratched all over it. 7) The tracks were rabbit-like and not that of another predator.