Abstract: Based upon the discovery thata porcupine attack of wood structures is due to the presence of sodium in the conventional resin used in the wood structures, the invention provides for replacing the base used in wood processing with potassium hydroxide or ammonium hydroxide or any other non-sodium base. Potassium hydroxide is found to be a specific deterrent to porcupines. A preferred resin formulation contains potassium hydroxide as the base, and an additive of potassium chloride in an amount of from 5% to 20%, and preferably 10%, by weight of the potassium hydroxide. The potassium-containing resin formulation may be used to make potassium-containing wood products, applied as an adhesive for gluing together wood objects accessible outdoors, mixed with a water-insoluble gum or paint or used to make potassium-containing panelling or shingles which are applied to existing wood structures to render them porcupine-proof.