I can also attest to "vermin" invasion. In a previous location, rats and
roaches ate blocks. I had to document (with pictures, etc. for risk
management) because of CAP requirements.
Also more recently, the blocks were stoe on site but a "fly" (I know because
we idenfitied from egg larve) ate blocks and laid eggs in a box- and also
had excrement left behind-so block storage needs to be in a controled
environment or I can see a chance of litigation. Stand your grong, site
these examples and if "the powers that be" decide to not pay for better
"control" -go on record with your requests. Good luck!