The building site was really short of men so the contractors decided to employ 4 cannibals.
The site foreman gets them started and shows them the canteen facilities 'all the food is free, so you shouldn't have any problems' he informs them.
'Great' say the cannibals.
After 4 weeks the foreman calls the cannibals back to his office. He tells them that one of the joiners has gone missing and asks them if they know anything about the disappearance?
The cannibals shake their heads - they know nothing. But after they leave the foremans office the head cannibal screams at his compatriots 'You bloody fools. - 4 weeks we've been eating architects, site agents and project managers without anyone noticing and then you had to go and eat a joiner!'