Yes traps....the rat goes underneath sticks it's head in and the co2 canister fires like a captive bolt thing....whacks the rat it falls down and kicks its self away in it's final throws of life...
Designed in NZ for controlling Possums...bigger of course...you can get different sized one for different species...
If set on trees for squirrel..they drop to the floor and you can collect them...or of course cleared away by predators...
It counts how many times it fires so you have a kill count...and it links to you phone
Expensive though£160 per trap