Some amusing comments... I do have an old microwave, think the mechanical timer wore out... Virus is a bad idea, wouldn't want the dog getting it. Hope to spare the squirrels, as they are a great help with the oak trees.
I think there was once a two care detached garage on the slab, gone long before I bought the property. Anyway, spent the morning clearing the ground around the slab down to the dirt, about 2 feet wide. Dumped poison cubes down the holes. Should be able to see any new activity. Hopefully exposing the area around the holes and the drowning will convince them to move on. Worked out an idea for some covers to put over rat traps. Will need to set some out where the dog can get at them, so need to make sure he doesn't (they hurt). Going to keep the electric ones on the porch, seem to work well there, and keeps the rats out of the house.
Messed around with a wireless camera, but need better battery to supply it, going to add a solar panel. It's color and 3 lux, so it'll suck at night. Got some 100 mA white LEDs, figure three ought to light up things well enough. Streetlight in the alley might help too. Have to work out a wireless on/off switch to conserve battery power.