Not all threats to a magic-user's pride and joy (i.e. library and/or laboratory) are elemental. Some come in the form of living things that destroy valued objects by infesting them. Where the threat of infestation is present, however, a spell is there to ward against it:
Proof Against Infestation
Spell Class: Magic-user
Spell Level: 3
Duration: 1 day per level of the caster upon exposure (also see below)
This spell provides total protection from infestation by rats, insects, and other vermin and creepy-crawlies for objects that would ordinarily be prey to such attacks, e.g. books, plants, alchemical ingredients, etc. The amount of material that may be so protected is equal in mass to one heavy book per level of the caster. This spell also provides potential protection from monstrous infestations, e.g. giant rats, green slime, etc. Any object protected by proof against infestation that is attacked by monstrous infestations is entitled to a saving throw versus poison made as if by a magic-user of the same level as the caster who originally cast the spell at the time the object received its protection. A successful save means no damage was sustained by the object and the creatures were repelled. The spell remains dormant until it is activated by contact with normal or monstrous creatures that attempt to infest the object. Once activated, the protection lasts for one day per level of the caster or until three saving throws have been rolled (whichever comes first).