I have 2 female rats that will be a year old in February. They are the first rats i have owned so i am still learning about them. One of them started sneezing a few months ago and does it often now but her appearance or behavior hasn't changed a bit. My other rat makes a funny noise every so often when she breaths that is hard to describe but also acts normally and doesn't appear to be sick. Is this something i should worry about? I don't have much money to pay for vet bills but will if necessary because i have become quite a rat lover. Thank you- Josh