New pullets three weeks in and the old hens still draw blood at the feeder New Flock

Separate the bleeding bird today, or at minimum cover the wound with something dark. Chickens are drawn to red and a small peck wound turns into a serious one within hours once they've all noticed it. Blu-Kote or similar purple wound spray is what most keepers use for exactly this reason.

On timing — three weeks with occasional feeder scuffles is normal. Three weeks with blood is not. Two feeders isn't really two feeders if they're within sight of each other; a dominant hen can guard both. Put the second one round a corner or on the other side of the coop so a bird eating at one can't see the other.

Age gap matters. 18 weeks against fully mature hens is a bit young — pullets integrate more smoothly once they're laying themselves, because their status changes. You're at the awkward point. It should ease as they come into lay.

Worth checking their crops in the evening too. A bird who is getting chased off the feeder all day will have an empty crop at roost time while the others feel like golf balls. It is the quickest way to tell whether the bullying is actually costing her food or just looking dramatic.

Add clutter to the run. Pallets leaned against the fence, a couple of logs, an old chair — anything a young bird can get behind so she breaks line of sight with whoever is chasing her. Open empty runs make integration much worse than it needs to be.

Check roost space too. Squabbles at the feeder often carry over from someone getting shoved off the perch overnight. Aim for at least 25cm of bar per bird and more than one height of perch.