The photo pretty much explains this method of mouse control. You can google bucket mouse trap or bucket rat trap and get all sorts of variations on the theme, many with crude execution. I have found that as long as you take in to account the size of the mouse, the geometry and spacing of the components, the thing can be pretty effective. We luckily have no rats, so I can't confirm how deadly it might be for them, as they are known to be pretty cagy.
Since we weren't living here full time till this past July, the buggers thought they owned the place. There is a new sherif in town, so things are clearing up.
Following this ( my first) mouse, I caught 38 more before winter set in and the water froze. The water is key, because they can actually jump back out if not treading water. Rats would have no problem at all jumping out if no water was there. I also found that this plastic pop bottle was better than a can, as it spun with just the right resistance, giving the mouse sufficient confidence to take that last fatal step.
Now that winter is ending, I'll start this bucket back up.
These guys all go in the compost pile, completing the circle of life.