You got to show them how to do it when they are about a year old. Get ya a hundred pounder or so and get in the pen with your dog. Get down on all four's and you go catcha pig on the ear with your teeth. Your dog will see that and go get the other ear. He'll be hitting ear everytime after that. Worked for me and got some hard hitting ear dogs

I dont care who you are, thats funny right there