A moist hide is crucial for a gecko as it aids in shedding. Geckos need a humid microclimate to help loosen and remove old skin effectively. Without it, they may suffer from incomplete shedding, leading to skin irritation or constriction, especially around the toes and the tail. Materials like sphagnum moss or vermiculite are ideal for creating a moist hide. These substrates hold moisture well and create a humid environment within the hide. The moist hide should be placed on the cooler side of the enclosure to maintain the necessary temperature gradient. Regular monitoring and misting to maintain humidity levels are essential for the gecko's health.