-How deep do you make your aspen substrate?
About 3" deep. They will burrow down to the warmth.
-Do the snakes usually poop on the top of the aspen or do they poop inside the aspen (in burrows, etc.)?
Usually on top, usually in the corners. Often inside paper towel rolls.
-How do you keep the aspen from getting into water bowls? I use heavy ceramic bowls, so I'm not worried about them tipping over.
It pretty much doesn't. I also use deep ceramic dog bowls. I have one male who spills- his bowl is in a 9" deli with a hole.
-How long should I freeze aspen to kill any wood mites, etc? I've heard overnight and 48 hours.
I've only had a problem with wood mites once, years ago. I buy on-line, not from pet stores. I'd go 24 hours.
-Do you guys ever worry that the aspen is too sharp/pointy/uncomfortable? I always wonder if the snakes are getting constantly poked in the eyes as they burrow. I know the scale that covers their eyes is tough, but still....
Thanks!