Siblings tend to squabble and fight, even as they age and mature. It is an inevitable scene in the household and even in public, and it can stem from many underlying factors like jealousy, lack of attention, or favoritism. A little disagreement is tolerable, but when the fighting and slight violence becomes excessive, it is time to put on your referee hat and sort out the issues.
Older siblings usually despise the kids after them because that means a division in attention. They tend to get more responsibilities, and parents always expect them to behave and be a role model to their younger siblings when sometimes, all they want to do is be a child as well. The solution to this is simple, but it requires a lot of work and effort from the parents. You have to make time for each child, and explain that having several children does not mean that they have to fight for attention, or that they are loved any less. Teach them about sharing, and instil in them the importance of family and sticking together. Instead of fighting each other, help them realize that they are a team and they should have each other’s backs. It would also help to talk over the fights they had and figure out how this can be avoided next time, and this will also foster better communication skills among children.
Don’t be afraid to enforce disciplinary rules and boundaries for their sake and safety, and give corresponding consequences if they start another rumble. But more importantly, work as husband and wife to make each child feel loved and secure.