An insulator for an electric fence having at least one wire is described. The insulator includes a body having a first end and a second end, a post connector portion at the first end of the body for connecting the insulator to a fence post, a wire attachment portion at the second end of the body, and at least one shield surrounding and extending outwardly from the body at a position away from the connector portion towards the second end, the shield including lateral portions on either side of the body. The lateral portions of the shield angle away from the second end of the body towards the first end of the body, such that when installed a straight section of the wire cannot bear against respective edges of both lateral portions simultaneously, and pass along their entire lengths, without contacting the fence post.