We just recently aquired a few breeding colonies of ICR mice and rats. We have been raising regular pet store mice for the last few years and want to switch over. My question is I am keeping the ICR's in a seperate room as I don't know if it is ok to keep them in the same room as the regular mice and rats. I have heard that ICR's immune system is not as strong as that of a regular mice or rat and that they can catch diseases off the common pet store mice. Is this all true? Any info would be appreciated.