Wow! I switched to the wood-pellet bedding for my rats. I never knew how loud it is! My rats like to dig it around their tanks, and it hits the glass, and it sounds like someone is shooting a bb gun in my rat reoom :) I like this bedding for its low-odor strength and economy.. but the sound really shocked me last night when I was home alone. I thought some ghostly hand was tapping the window.. :O