Adopted a sweet female rabbit so it could have a home but my other rabbit does not like her?

Maybe Mittens is angry at Epic because Hershey is her mate. Or, my best guess, is that Hershey was spraying his scent when he got near Epic and it was Mittens terratory, so she attacked. She might just be trying to ert her dominance. Good luck to you. I myself cant figure out why my male and female bunny don't get along.