Repel vermin

Repel vermin is an abjuration spell that causes insects and other vermin to stay at least 10 ft away.

Effect
An invisible barrier holds back vermin. A vermin with less than one-third your level in HD cannot penetrate the barrier. A vermin with at least one-third your level in HD can penetrate the barrier if it succeeds at a Will save. Even so, crossing the barrier deals the vermin 2d6 points of damage, and pressing against the barrier causes pain, which deters less aggressive vermin.