I have had backyard chickens for over a year now. I've naturally brooded virtually all eggs ( barring unforeseen complications) under broody hens. All of these hens have been fierce protective mothers and I've been able to leave them among the rest of the flock from the moment of hatch. Yesterday one of my youngest hens hatched out her first brood. 6 chicks total. This morning I was out back when I noticed one chick having difficulty staying with the group. I approached and saw a severely injured wing. Clearly the chick had been attacked. I brought it inside and did what I could. Its wrapped and safe but honestly i cant say whether it will live but even if it does that wing is probably going to be useless. Anyway after chick triage I went back outside to check on everyone and get some chick starter for my little invalid when I saw that mama hen was down another chick. I started looking around when I finally saw one of my oldest hens with the missing chick in her beak. She had been pecking at it and picked it up and run away with it when I approached. The body was pretty mangled. I'm certain she killed it and was responsible for the other chicks injury. I think my new mom just wasn't fierce enough in protecting her babies and my most senior and aggressive hen took advantage of that. At this point since my older hen has killed a chick should I get rid if her? I worry that much like egg eaters once started they will continue to do it and possibly get other chickens involved. I've removed the killer hen from the flock and I've got mom and remaining chicks in a bin while I figure out next steps . Any suggestions would be appreciated. I've never dealt with anything like this so I'm in completely uncharted territory here.