Hello. I was wondering if anyone could help me. I have 6 chickens in a 5x3 foot coop and 14x7 foot run. Plus when we are home they have the whole of our large garden. I have:- 2x Hyline browns 1x Light Sussex 1x Gold Laced Orpington 1x Speckled Sussex 1x Buff Sussex. They are all about 6 months old. I got the Hyline browns when they were 1 week old so that my kids could experience having chicks and the pure breeds I got as POL. The Hyline Browns were the first ones in the coop in about December. We then added the Light Sussex and Gold Laced Orpington (who were a bit older and bigger) in about February. All was good and they all got along perfectly without any pecking. Two weeks ago we decide to get two more chickens from the same breeder as the LS and LGO so we added the Speckled Sussex and Buff Sussex. We added them at night and for a day it all seemed ok. Then both the Hyline Browns started viciously attacking them. They would jump on their backs and pin them down with their talons and then bite their necks and back. This happened everytime the SS and BS came into the run. so for days they just stayed in the coop (unless the Hylines chased them out!) Even the LS and LGO would give them the occasional peck but nowhere near as brutal. This also happens when they are in the garden, so I don't think it's a space issue they seem to have a genuine hatred for them! I separated the Hylines in a run within a run and at night I made 2 nesting boxes into 1 and put them in there. I did this for about a week and then yesterday I decided to let them a share the run. Within seconds both Hylines went straight for the Speckled Sussex and pinned her down and started attacking her. Straight away I put them back in there own run. I asked the breeder for advice and he suggested spraying all the chickens with watered down vinegar so that they all smell the same and if that doesn't work get a rooster to keep them in line. I was thinking of removing the Hyline browns totally for a few weeks and the re introducing them to see if that helps. I'm a bit worried about just leaving them to it and letting nature take it's course because it really is quite brutal, it looks like a cock fight! Does anyone have any ideas? Thanks for your time. Steve.