A puncturing tool for small animals which has a novel structure, facilitates confirmation of the connection state of a capillary tube, and can prevent inadvertent detachment of the capillary tube. A puncturing tool for small animals includes a connecting part for a capillary tube on the proximal end side of a hollow needle, wherein the connecting part has a tapered peripheral wall that expanding and extending in a direction away from the hollow needle, and a tapered peripheral wall has an elastic fitting part, through which the capillary tube is inserted, projecting inward from a middle portion of the tapered peripheral wall in the length direction thereof.