PROBLEM TO BE SOLVED: To provide an adhesive that uses a resin derived from biomass as a raw material and is excellent in not only heat fusibility but also durability and to provide an excrement- treating agent for a pet that is produced by using the adhesive.SOLUTION: The adhesive comprises a resin. The resin is produced by subjecting a dicarboxylic acid component including a dicarboxylic acid compound having a furan ring and a diol and/or a diamine to condensation, has a content of the dicarboxylic acid compound having a furan ring in the dicarboxylic acid component exceeding 90 mol%, and has a melting point of not less than 50°C to not more than 200°C. The excrement-treating agent for a pet is produced by extrusion molding the adhesive and a pulverized product of a woody material at a temperature equal to or higher than the melting point of the resin contained in the adhesive. An adhesion method comprises adhering using the resin.
