Original question from Quora
“You need to separate them immediately or someone could get seriously hurt or killed even.
Put their cages near each other so they can chat and see each other, but don’t allow any touching whatsoever.
See what happens when they’re adults, but be prepared for them not to be together”.
Without watching them we don’t know if it’s dominance or jealousy.
In multi bird, cages, it’s best to place multiple food and water dishes, also separate sleeping perches.
Then create “safe zones” from enrichment toys or even Romain lettuce clipped to the cage walls so any bird can get privacy when needed.
Yeah like you never wanted to crawl into bed and be left alone.
My guess your cage has few toys or accessories so your birds have nothing to do except pick at each other.
10 budgies, 4 years, no eggs, no fights.
(10 budgie aviary)
Lastly, introduce lighting over the cage top with a timer.