you must tell the dog no!! everytime he goes near them. if that doesn't work carry a squirt bottle with water ans squirt at him/her when they go nest them. Or you can get a pepsi can fill it with...
Give a loud, shrill "yelp" sound the way a dog would if bitten, followed by a "no" command. Do not hit the dog. Whenever there is no biting going on, use lots of positive reinforcement (like saying...