That is a great question. I too have hatched out many colubrid eggs on a shelf at room temperature, in a box full of damp substrate. Usually spaghnum moss. The temps fluctuate from high 60's to mid 80's. I have never seen a kink either. It makes me question if another factor, maybe intensive inbreeding, can cause kinking. I know indigos are prone to kinking and the captive population is small and pretty inbred.