100 yrs ago (feels like), I lived in a hippie household in Glebe Sydney, right by the water. We had a huuge problem with rats and all sorts of vermin.
All the "floaties" (dead animals etc) that choked the waterways attracted them. Rats the size of cats, the size of dogs. They'd eat through heavy storerooms doors
at night, and small 22 rifles would just annoy them. So, we made up a HV HE trapdoor. It was mounted high up and when the rat walked to the center, they were
hit with a vh energy pulse. We used various grids / cloth covered plates. The trap door opened and it'd fall into a 44 gal drum of water, making sure it drowned
if not dead. For the first few weeks, we filled the drum each night !! A "one off" approach was pointless. They bred faster than we'd be able to kill them.
Soon after, Sydney had a massive clean-up of the waterways and life went back to normal.
Maybe a similar system would be better. Doesn't need to be HV electric, but something that doesn't require resetting, and "dumps" the body.