Never had a problem with Indominus rex, But then I don't dare keep one on Isla Pena. Ol' Rexy was enough of a handful, escaping after every storm, until I got Electric Concrete Walls, And just Tranqed her during every storm. 
Although my first Indominus rex did kill it's sibling. But then I expected and wanted that to happen. It's kinda cool, if It's actually what happened, when you first breed them they'll tolerate a social of 2, but then change over time. At least it seems that's what happened.
(really hope it did, because that would be a really cool little detail
)
Although my first Indominus rex did kill it's sibling. But then I expected and wanted that to happen. It's kinda cool, if It's actually what happened, when you first breed them they'll tolerate a social of 2, but then change over time. At least it seems that's what happened.