Pest Control To The Resue
Instead of taking on the job themselves, they called in pest control to deal with the problem. But first, they managed to pinpoint the origin of the noise by mapping out where they were hearing it and figuring out where it was most prominent.
By the time they called pest control, all that needed to happen was for them to mark where they were going to pump their rodenticide. Rodenticides are pesticides for rodents and come in many different guises, from edible pallets to dilutable liquids that can be sprayed. They are toxic to humans, though.