Hmm now that Wilomn mentioned it, two american blues that I had(but did not breed. They weren't related to my stock), suffered inner ear problems. When I found them dead, there was blood pooling out of their ears. At the time, I just wrote it off as them getting in a fight....
And no to the Siamese being aggressive. All of mine are sweethearts. My favorite rats are all Siamese because they are so social and gentle.
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