Today I noticed a head wound on one of my baby rats (3 mos old). It was no longer bleeding by the time I saw it. She got it sometime today, I suspect from her sister. Her sister had the wet sneezes all day today, so I suspect that she was feeling unwell. I've dabbed the wound with salt water and put polysporin on it for now. However, her sister (who is the only rat living with her) won't leave her polysporin head alone. I'm not sure if it's better to keep them in the cage together, or put the wounded one in a separate cage - even though being separated will stress her out. Thoughts?