“…On the ceiling, it mainly consists in dissolution by condensation water. The limestone cement is removed in solution, and the weathered limestone remaining on the surface is eventually disaggregated and falls by gravity (Zupan-Hajna, 2003) and by the successive use of the claws of roosting bats (Merino et al, 2019). This ceiling disaggregation can produce a rain of sand (Delaty et al, 2006).…”