An small-animal-controlling resin composition includes at least a base resin, a small-animal-controlling agent, a sustained release auxiliary for the small-animal-controlling agent, an organic weatherproofing agent, and metal oxide fine particles as an inorganic weatherproofing agent. Surfaces of the metal oxide fine particles are subjected to a surface treatment using a surface treatment agent comprising an organic material. A low volatility carboxylic acid ester derivative having a boiling point of no less than 200° C. is used as the sustained release auxiliary for the small-animal-controlling agent.