I'm a little sad for this post but mainly frustrated!
I have 2 female rats and one male. He knocked them both up and are going to have their first litters in a couple weeks. However, I found bite marks on the beige female and moved her out separately.
A couple days later, I found a large bite out of the back of the black female's back. Ugh... So I moved her to a hospital tank and she healed just fine.
Last night I put the females together, and I went to check on them this morning and the black rat had been nipping at the beige female quite a bit.
They are separated completely now but I really wanted to keep them in a group and am highly frustrated that I am wasting 3 cage spaces for what should have only been one main tub and one birthing tub.

Any suggestions?