Have you tried the motion sensor automatic sprinklers?
They work great 
Got rid of several damn Deer and many other critters that thought they owned the place 
As you I hate to kill them and will try anything not to have to kill them
Cute little smelly things 
How about Flickers as in lareg destructive wood peckers they drill holes in the house 
So long as they are a longs ways away from me I have not problems 
Eat my house I have an issue that wil be resolved soon