Nonlethal rodent repellents: Differences in chemical structure and efficacy from nonlethal bird repellent.

At least some anthranilates (e.g., methyl anthranilate), and acetophenones (e.g., orthoaminoacetophenone) are aversive to mice as well as to birds. Here we systematically examined nine acetophenone isomers (ortho, meta, para) and moieties (amino, hydroxy, methoxy) previously tested as drinking and feeding repellents for European starlings (Sturnus vulgaris). All nine substances reduced intake by mice in single-bottle tests. When molecular characteristics were examined, amino group reactivity and, to a lesser extent, isomeric position (i.e., resonance), were related to the strength of the avoidance response. Unlike effective avian repellents, the presence of intramolecular hydrogen bonds did not appear to affect avoidance responding.