The Rat Catcher

I hope this one is ok :D

A group of Sales Reps are drinking lunch in a pub one day and the discussion has just got round to the company car and how it 'defines their place in the company' when a brand new Rolls Royce pulls into the car park; out steps a rather scruffy individual who makes his way to the bar. He orders a pie and a pint and looks round the bar, nodding to the Reps.
After several minutes, one of them can stand it no longer and asks if it's a company car; the answer is affirmative so the second question is who is his employer. Taking a swig of his pint, he tells them that he works for the local council. This is met with some disbelief by the assembly, who then ask what his position is with the council.
Finishing his pint, and waving for a refill, he states that he is a Rat Catcher, and as such has been the biggest single source of revenue to the council for several years, having brought in several million pounds each year. This is met with some disbelief as there is no way a dead rat can be worth anything.
With a laugh he starts to explain that for every rat killed, the council receives $2 from the government: the rat skins are sold to a company which makes fake furs out of them and pays $1 each for them. The meat is boiled of the bones and goes into dog food and brings in $1.5 per kilo. The bones are ground up to provide fertilizer which brought in $3.50 per kilo, but are now much in demand for better quality dog food and now bring in $3.75 per kilo, all in all quite a respectable total.
The Reps remain sceptical, as they feel that this can never justify the Roller.
The Rat Catcher smiled and then added that there was also the rat and that that contributed the greatest part of the income, bringing in $4 per kilo from a local tool manufacturer, and that it was sold to them by the ton. The Reps, now in total disbelief, challenged this and demanded to know what possible commercial use there was for rat .
Finishing his pint, and turning to leave, the Rat Catcher asked if they had never heard of rat handled screwdrivers