We just instituted "the change and wash before handling rule" for those days we have gone to pet stores...lol. I am concerned about substrate now. How do I know if it's "clean". We bought a block of cocochip. We only broke off what we needed to his cage, the rest is stored in another part of the house. Do I toss it? If I buy a new block, how do I know it's not carrying eggs from wherever it comes from. He will be using paper towels for a while, but the cocochips really work well keeping our humidity in check.