Rats are neophobes. If you happen to have a rat problem, and want a humane and organic, if not altogether neighbourly, solution, it pays to play on this. Disrupting a rat’s routine, by steps as simple as identifying a daily route and placing a different object such as a bucket or a gnome on it each day, preferably at different times, will soon stress the rat. Keep being inventively random in your changes and you’ll soon cheese off the rat so much that it will just up and leave, moving to somewhere close by, but with none of that pesky change.
The rat sees no benefit in the changes you’re making, there’s no upside to the rat, so why stick around when things are just complicated and confusing. You do need to be careful to get it right though.
If the rat sees a bird feeder on the other side of the bucket then it might just motivate him to walk around the bucket. If it noticed other, healthy, happy rats doing very well after climbing over the bucket it might make the effort. If the changes you were making happened in some form of predictable order, and built upon each other rather than each just replacing the last, the rat is likely to see the pattern and become less stressed.
If you introduce the new items steadily, moving them in from across the garden, the rat will get used to the idea, settle in to the new routine and see no reason to run off, so be sure to always spring each new change as a complete surprise to ensure your rats reach intolerable stress levels if you really want to be rid of them.