I've used pine shavings for more years than most members here have been alive. I've used aspen too, had no problems, but it took too much compared to pine shavings, volume wise, to make it cost efficient.

I keep both mice and rats. I can't remember the last time I heard a sneeze or a cough from any of my rodents.

I've been keeping my snakes on pine longer than I've been breeder rodents. I don't use wet pine. I did learn that lesson the hard way many years ago before I even knew what a turpine was. Now I stick to well dried shavings.

The only breeder rats I've lost in the last as long as I can recall are pregnant females that died in childbirth. They are almost always either first time mothers or giving birth during the heat of summer. I have not had a male die in longer than I can remember and there have been MAYBE half a dozen females out of probably a hundred or so that have rotated through the breeding tubs.

I keep my rats in the snake room so they have heat during the winter, in the 80-84F range and A/C in the summer to keep them about the same EXCEPT on those days when it's 115F here and the A/C isn't quite up to the job. It may hit the mid 90s for a while on those days and I have noticed that those are the days that I have had mothers die giving birth.

I have no problems with babies. I don't always keep count but I can recall, mostly, how many are in each tub from week to week.

Those of you who have seen my snakes know they look pretty good. I RARELY feed anything I haven't produced myself, ratwise.