I think they all have it,its just more pronounced in homers. I raise rollers and have had them come long distances when they were sold or given away. Doesn't always happen. Have had others get lost a half a mile from home and take up with wild flocks! Like the other guy said ,I would not mix as it will ruin the valvue of your purebred birds. If you still want them,pen them separate and use them as feeders for your homers. Wild pigeons are just as enjoyable as the fancy breeds. Thats what I started out with some 45 years ago!