More interesting info from A1 :-
"In the 1980s, Rentokil predominantly used the Daystate Huntsman, a rifle specifically commissioned for their professional pest control operations.
Key Air Rifles Used
Daystate Huntsman (Original): Commissioned in 1980, this was the first modern smallbore Pre-Charged Pneumatic (PCP) air rifle. It was designed to deliver high power—approximately 40 foot-pounds in .22 caliber—making it highly effective for extermination tasks.
Daystate Huntsman HL: A simplified, lightweight version of the Huntsman specifically developed for Rentokil technicians to use in the field.
Daystate Air Ranger: While Daystate's first product was originally a tranquilizer gun for larger game, it was the precursor to the specific pest control models adopted by Rentokil.
Why These Rifles Were Chosen
Accuracy: As PCP rifles, they had virtually no recoil compared to traditional spring-powered air guns, allowing for extreme precision in urban and industrial environments.
Power: The custom-built nature allowed for power levels far exceeding the standard UK 12 ft-lbs limit for unlicensed users, providing the "stopping power" needed for professional pest management.
Reliability: The partnership with Daystate was so successful that many of these original rifles were still in service or being repaired decades later".