I roll the big magnet over the ground near the barn and coop every year, and find amazing things (old farmstead). It's hard to manage every single nail/ screw when building, and they reappear every spring! One nail can kill a horse, not to mention the chickens, and I'm paranoid about it. That doesn't mean it will ever be clear ground! Mary
The ones that roll look like they would be a lot easier to use than the one we have.