Poop eating is very common in beagles and usually isn't because of food. It's very gross to us but kind of natural to them but not a good habit because they can get worms. We have had many poop eaters over the years and the best way to curb it is to be out there with them to tell them "no" and then scoop in up immediately. You can try calling them away from the poop and rewarding them with a treat if they leave it.