Welcome to the new science of Blue Iguana reptile substrates. In the past, a reptile substrate was considered a litter- merely a convenient way to dispose of reptile waste. Blue Iguana reptile supplies recognizes a substrate to be the primary factor in creating a specialized environment tailored to the needs of specific types of reptiles. A substrate may supplement an animal’s mineral needs, or humidify its surroundings and determine the pH of the physical environment. A substrate can also be utilized to biologically reduce toxic animal waste to provide a cleaner environment in between changing.