The principle of this is getting rodents to climb a ramp to get to the top of the bucket for bait, but then the board gives way, and the rodent falls into the bucket and can't escape.Can you amplify this a bit? What makes the mice or rats want to check out the 5 gallon bucket of water, and what did you use as a trip? Was there a partial lid to keep them from climbing back out?
As far as I know, we don't have mice or rats (yet), as I think the presence of the cat drives them off, but I don't expect this to last. I'm thinking of setting up traps in the yard, not in their run, to discourage any exploration by rodents.
You could find lots of DIY ones, but here's one you can buy that gives the idea.
