Native bees don’t build hives. Instead, they dig holes in the ground or live in holes. Some, like carpenter bees, chew the holes themselves. Others have to find their holes pre-made. This is an experiment using some old cut-up stumps, to see if any bees will move in. If they’re acceptable, the bees will nest in them and cap the opening with silk. So far, impossible to say if this real estate is attractive.