Aside from late paycheques and water-cooler gossip, the burning question of who is pillaging office milk can be one of the most contentious issues in the workplace.
Instead of going to great lengths to protect your precious dairy from the wandering hands of your colleagues, such as adding a padlock, one expert recommends applying a theory made famous in a Hollywood film to the little game of cat-and-mouse.
Robert Hoffman, an economics professor at RMIT, is an expert in game theory - an approach to psychological warfare made popular by the Russell Crowe film A Beautiful Mind - and says it can be used to stop milk theft once and for all.
PRETEND YOU ARE THE BOSS
A surefire way to protect your milk from mysteriously disappearing is to provoke fear in the minds of your thieving co-workers, Robert told Australia's ABC.
Simply scrawling the name of your boss on the milk in black marker will safeguard the bottle from even the most audacious kleptomaniac in the office.
Most employees, if they value their job and respect the boss, will not risk stealing their superior's dairy and will avoid your milk like the plague.
Robert describes this move as the "chicken game" but warns it doesn't work if multiple co-workers have this same bright idea.
BEAT THEM AT THEIR OWN GAME
When all hope seems to be lost, stooping to the level of your light-fingered workmates might just be the answer.
Stopping the crime by cutting off the supply and stealing for yourself instead works as a solution and is an example of "prisoner's dilemma", another offshoot of game theory.
But this tactic, much like the milk which acts as the catalyst for this mind game, has an expiration date.
"Prisoner's dilemma" applied to this situation means you are simply relying on the other co-worker to unknowingly hold up their end of the deal - but when they eventually fail to buy milk, then you both lose.
CREATE A MILK ROSTER
Despite the tired story of office milk crime always involving educated and professional adults, sometimes the answer is creating a basic milk roster to stop the theft in its tracks.
This is known in game theory as the "public goods game" where the "tokens", this being the milk, are divided evenly among the players. It works best when everyone contributes but this isn't always the case.
"By observing what other people are doing, by learning and, sometimes, punishing each other we can establish co-operation on the milk issue," Robert told the ABC.
Other foolproof tactics office workers have shared include putting dye in the milk to convince others it has gone bad, putting a padlock and chain through the lids, keeping long life milk under your desk or sensationally labelling it as "breast milk".