mice...question??

[Christmas_Hamster]

Also I was told males usually bite?

I do not think this is true I think it would depend more the individual rat not the gender.

Don't use cedar either, vet said that it causes upper respiratory infections in most small animals.

Or pine. It causes respiratory problems as you mentioned, can cause hair loss and liver damage as well. The pheonals(sp?) from these shavings cause this and it usually shows up over long periods of time. Just like a human smoking does.