Growouts fighting at specific times, I can't find the cause

[Naelin]

We weaned 2 litters (10 kits total) at 8 weeks to a colony-style pen some weeks ago.
Since then, there have been several instances of fighting, all involving running in circles chasing each other until eventually two would get in a death ball.
We figured out two of the three males had been the worst aggressors and butchered them, and separated the third when we saw the girls were still getting nasty.

But now, the girls are still occasionally getting in fights specifically when we let them out of the hutches in the morning. They get too excited, start zooming around, zooming turns to chasing, etc. There doesn't seem to be any specific aggressive one now and they are only 11 weeks old. The litter is otherwise incredibly well-behaved, super sociable and love to sleep against each other.
Are there any potential reasons this might be happening or things I could do to prevent the infighting?

 

[RabbitsOfTheCreek]

If it's only happening in specific places then it's probably something else to do with that place
But other than that I just have litters that get along well and some that don't

 

[tambayo]

You are saying hutches for the night and a bigger enclosure during the day?
I hear from some people with pet bunnies that the difference in living space/size can trigger agression, some becoming territorial and such. They are fine when the living space remains the same always.

 

[Naelin]

If it's only happening in specific places then it's probably something else to do with that place
But other than that I just have litters that get along well and some that don't

It has also almost happened twice before they were weaned so they were living in a different area. They went into a whirlwind chasing their mother, but didn't get to fight because they were distracted when we went to check what was happening.
You can see a picture below. One of the females was mounting another (they were about 6-7 weeks old there) and all from the same litter.
Right now they are all from the same litter as well (save from one that is a sibling but was fostered to another mother). So it doesn't seem to be dependant on the location or having a different litter with them...

 

[Naelin]

You are saying hutches for the night and a bigger enclosure during the day?
I hear from some people with pet bunnies that the difference in living space/size can trigger agression, some becoming territorial and such. They are fine when the living space remains the same always.

That is very interesting, it could be the cause since it seems to happen when they just get released from the hutch... sadly having them out day and night would mean that the only male doesn't get scheduled time out of the hutch but it may be worth it until we process the rest of the culls

 

[Alaska Satin]

That is very interesting, it could be the cause since it seems to happen when they just get released from the hutch... sadly having them out day and night would mean that the only male doesn't get scheduled time out of the hutch but it may be worth it until we process the rest of the culls

Rabbits need a dominance hierarchy. It takes a while to work things out among a large group of them, especially if they've been living in groups where they've already established a hierarchy, so that there are several rabbits who think they're at the top.

If you want to keep letting them out, I'd give them as big a space as possible, and lots of hiding places. I'd also make sure there are multiple sources of food and water, because resource guarding is part of both establishing and maintaining the hierarchy.