http://www.trifl.org/cedar.shtmlAFRMA - Both cedar and pine contain phenols-that's the stuff that makes them smell good. Phenols are caustic, poisonous, acidic compounds. These compounds cause constant irritation to the nasal passages, throat, and lungs of small animals giving bacteria an easy opening, thus commonly causing pneumonia. Phenols also affect organs such as the liver and kidneys, because these organs are responsible for filtering toxins out of the body. When presented with a large amount of toxins over time, they are unable to filter it all out and begin to fail. An animal with a damaged liver will have a depressed immune system, which can lead to other medical conditions.
And so on.Although wood chips may provide a natural means of insect and odor control, "natural" does not always mean safe. These same chemicals can also damage the respiratory tract, causing chronic respiratory disease, and asthma, and some studies have found an association between exposure to some wood dusts and oral cancers. The scientific literature on this topic is extremely clear, and unlike many studies of toxins, most of the scientific evidence regarding wood dust exposure has been conducted in humans rather than in laboratory animals since so many people work in the production of wood products.
I use 50/50 peat moss and coco fiber for all of my snakes. Some would argue that it's an impractical substrate because the snakes have a higher chance of impaction. I feed f/t on a large area of thick newspaper and problem solved. The substrate makes humidity easy to maintain and it's a cinch to scoop up after the animal defecates. Not only that, but if you enjoy natural looking enclosures, like I do, it's a much nicer looking alternative then newspaper etc.
With that said, all new snakes are put on papertowel for the first three months in an isolation room. Peatmoss/coco fiber make's it hard to spot external parasites, and even harder to treat them. I also get frequent fecal floats done to test for internal parasites in new animals, obviously it's easier to obtain a sample if the snake's not on a fluffy substrate.
What difference does it make? The substrate aids in meeting husbandry requirements for both snakes and tarantulas...but this is a snake man not a tarantula or scorp your talkin about.