An insulator for an electric fence having at least one wire, the insulator including: a body having a first end and a second end; a wire attachment portion positioned at the first end of the body; a post connector portion at the second end of the body, for connecting the insulator to a fence post in use, wherein the wire attachment portion includes a passage passing through the wire attachment portion, the passage including a first open end, a second open end, and a waist region between the first open end and the second open end, wherein the diameter of the passage at the first open end and the diameter of the second open end are both greater than at the waist region, wherein the passage flares out from the narrow central waist region to the first open end and the second open end, in a curved flare, wherein the wire attachment portion includes a wall having an interior surface defining the passage, and an exterior surface, wherein at least a portion of the exterior surface of the wall between the passage and the body of the insulator is shaped to approximate the shape of the interior surface of the wall, characterized in that: the body, the wire attachment portion and the post connector portion are made of an electrically insulating material, and wherein the insulator as a whole is moulded as a unitary part, and wherein the body is connected to the exterior surface at the waist region such that an electrical creepage path, from the passage to a post to which the insulator is secured in use, passes along the exterior surface and across the body. a body having a first end and a second end; a wire attachment portion positioned at the first end of the body; a post connector portion at the second end of the body, for connecting the insulator to a fence post in use, wherein the wire attachment portion includes a passage passing through the wire attachment portion, the passage including a first open end, a second open end, and a waist region between the first open end and the second open end, wherein the diameter of the passage at the first open end and the diameter of the second open end are both greater than at the waist region, wherein the passage flares out from the narrow central waist region to the first open the passage including a first open end, a second open end, and a waist region between the first open end and the second open end, wherein the diameter of the passage at the first open end and the diameter of the second open end are both greater than at the waist region, wherein the passage flares out from the narrow central waist region to the first open end and the second open end, in a curved flare, wherein the wire attachment portion includes a wall having an interior surface defining the passage, and an exterior surface, wherein at least a portion of the exterior surface of the wall between the passage and the body of the insulator is shaped to approximate the shape of the interior surface of the wall, characterized in that: the body, the wire attachment portion and the post connector portion are made of an electrically insulating material, and wherein the insulator as a whole is moulded as a unitary part, and wherein the body is connected to the exterior surface at the waist region such that an electrical creepage path, from the passage to a post to which the insulator is secured in use, passes along the exterior surface and across the body. the body, the wire attachment portion and the post connector portion are made of an electrically insulating material, and wherein the insulator as a whole is moulded as a unitary part, and wherein the body is connected to the exterior surface at the waist region such that an electrical creepage path, from the passage to a post to which the insulator is secured in use, passes along the exterior surface and across the body.