Occasionally, it occurs that for no apparent reason, a snake does not shed. The housing conditions are correct, and the snake goes through all the different phases of the shedding cycle, except it does not actually shed its skin, nor does it even attempt to cast its skin. By the time the keeper finally realizes this, the old and the new layer of skin are already hopelessly stuck to one another. Some long-time keepers with large collections are familiar with this phenomenon. The cause of this is unknown. Luckily, these “refusers” usually go through another shed cycle shortly afterwards, which then progresses normally.
