I think I figured out the problem with the bugs.

I bought the "suspected" buggy bag of the Feline Pine at a feed store. I noticed little holes in the bag, but figured it was from them stacking bags on top of each other, making the pellets cause the holes, so I paid no attention.

Well, I went to the same feed store this weekend and bought another bag, but didn't notice the holes in the bag till I got home. Since it was late while I was changing the boxes and the store was closed, I used it anyway. I did mark the boxes I used that particular bag in and will watch it for bugs again. The other bags I bought from PetSmart had no holes.

I'm figuring either there are mice or bugs in the warehouse that are somehow getting in the bag and causing the problem. If I get bugs again, I'm going to PetSmart from now on.

The only reason I've gone to that feed store is because they match the prices of PetSmart and PetSmart is a little further to travel. Looks like I'm making the trip!!

Just to be on the safe side, I'm also going to check the bags before I buy!! Better to be safe than sorry.