Jeff, encouraged by your success, I went for the Rat Zapper (Ultra) from Amazon; and after making a weather protection enclosure for it, I put it out in the yard, hanging on the side of wood fence.
First night, nada.
2nd night: hey, I saw red LED blinking. Sure enough, that is the tail of a rat I saw! I suspect, more rats and squirrels will frequent my yard as my trees start producing fruits.
I used to use traps made by "Have-a-heart", they worked great, the trouble is--for me--after trapping them alive, then I need to go find a location to release them...; but using Rat Zapper; just tossed it in the bag and into the waste bin...
Just wondering Jeff, how long (or how many zaps) that 4 D size batteries last you? Thanks!
My first victim, baited with cut cheddar cheese: