IME, most biters change behaviors in new settings. Terming a biter can be in the best interest of the child.
Sometimes it isn't about the room, toys, activities or routine at all. Sometimes it is simply about
rank. If a child is the oldest at home, used to leading and is now expected to yield and dismissed as "the baby" they lash out to get back out front. If a child is the youngest and used to be protected/guided and is now expected to lead feels unprepared and lashes out for safety, "who's got my back??". Familial roles and group rank are still an important part of human development.
You know you see it in the workplace, too, when you get new leads or assistants.
If you can't support rank needs by making some changes (ratio, space), then allow them to join another group where they feel comfortable, safe, wanted and appreciated.
I got rid of biting many years ago by only enrolling infants. I did not fully comprehend how it worked at first, it was just a theory I had, but it has panned out beautifully. When I do have to fill a toddler spot (rare), I try to choose the personality/rank that will best support the group and individuals needs. I tell the parents why so they can consider it, too. It matters in all of their playgroups.
I hope that made sense. I am overcaffeinated this morning, admittedly.