It's reassuring to know the bear won't eat it like a tick-tack. We've had issues with our deer cane disappearing up north. These big rocks get knocked down from time to time, but don't just mysteriously disappear!
When you put your rock out, choose a somewhat secluded location. The deer need to feel comfortable, not fully exposed in a field. We've had good luck by water sources, it seems to satisfy more than one need & boost visits! We chose by a lake & drainage creek.
The deer will hit the rock hard when they're antlers are growing. That's why now is an IDEAL time to place out some rocks. It's also beneficial to nursing does & wandering yearlings.