My 2 l.parahybanas seem to be in premolt. They havent eaten for 3 weeks and their abdomens turned dark aprox 4-5 days ago and I was wondering if it would be a bad idear to change their soil at this time or if I should wait until they have molted?
I would wait. Unless it is a matter of pressing urgency, like rampant mold, mites or flies, I would let them be until after they have molted and recovered from it. Moving them around close to a molt could potentially damage the developing exoskeleton and lead to molting complications.