Fighting Muscovy ducklings?!

[amygrace]

starting this morning, four of my eight 6 week old ducklings began fighting aggressively in pairs.
One would peck the other and then they would squabble. We let them go for a minute thinking it would sort itself out but they were still hard at it.
we separated them then let them go again after a minute and all was fine for 5 minutes before it started up again with another two starting to fight once the other pair did.
This has continued for the rest of the day with us putting milk crates on the aggressors for a 5 minute time out.
When they rest in a group one will shuffle around on its belly to get next to another aggressor duck and with one peck it starts and the other pair start as well. we have Marked them with harmless wound spray for birds so we know it's the same ducks each time and size ranges from the biggest to smallest of the ducklings
Nothing has changed in routine, they did have a big feed of kale yesterday but have eaten it before, otherwise there have been no other major changes, besides the wet weather. they are housed with guinea fowl Keats But are are having no issues with them at all
They eat duck mash, worms, bugs and fresh lettuce, kale, silverbeet, fruit, cooked veggie scraps and grass, as well as a morning and afternoon warm water swim.

Any help or insight anyone may be able to give me would be very appreciated!

 

[Buck Oakes]

Ok do all in your power to separate them, but agressors with aggressors an non agressors with non agressors in pairs of two, the agressors won't fight each other because of their rank an the mom agressors just want fight so that should help, also they could be fighting I've food because of competition so again it woul be best to seperate

 

[amygrace]

Thankyou! Iv separated them already, all aggressors are under milk crates together because even in pairs they end up fighting, it can't be food, in the pen there's 4 separate sets of food and water and grass just hope they settle, they've been brilliant up until yesterday when something just snapped and changed...
Thankyou!

 

[Buck Oakes]

Make sure they're area is very large they could also be fighting over space they new about 5 feet per pair I know it's a lot of work but I promise your results will be amazing also take them outside under grey protection , grass real eases a chemical tht soothes their stomachs and stuff so maybe that might make them feel better as well