I will add the airline exterminators use the old fashioned method to kill the rats- mouse traps with peanut butter- the one I saw measured in at 16” from head to tail….
On your next flight when you hear the litter patter of tiny footsteps from the overhead and sidewalks, realize you are not imagining things….best to report it to the senior FA and get the pilot to make a logbook entry.
In my area we have a 1/2 ton of cats. No mice or Norway rats. Still have moles and shrews though.