LUIS Suarez should know that the rules of the playground apply when you are roughing up an opponent on the sports field.
By all means kick someone in the head, and as in the case of Paul O’Connell only eight days ago, you might just get away with it.
You might punch someone, and as long you were part of an ordinary decent brawl, nobody is going to get too bothered.
But don’t, whatever you do, bite.
We seem to have curious double standards when it comes to violence on the sports field.
Many a dull rugby international has been livened up by 6 ft 6 giants trading the sort of haymakers that would make Iron Mike Tyson blush.
The great BBC commentator Bill McLaren used to describe this sort of prolonged fisticuffs euphemistically as “a wee bit of argy-bargy”.
In GAA it might be termed “getting to know each other”.
As chewy Suarez has no doubt discovered, biting is treated as something entirely different – and this harks back to our days slugging it out in the schoolyard.
It was quite within the rules of playground scrapping at my school to give someone the stiff arm swipe, a flying Kung Fu kick in the style of Eric Cantona, a twist of the arm known as “a Chinese burn”, and other forms of minor torture.
I am pretty sure we discovered waterboarding before the Americans, and for some it was the only decent wash they had all week.
But amid all this peer-approved violence biting was off limits. It was considered a bit girlish.
It was almost as bad as pulling someone’s hair. It seems to be the same in the adultescent world of football.
The Professional Footballers Association has apparently offered Luis Suarez anger management counselling in order to cope with his Hannibal Lecter tendency.
But Dan Walker was perhaps right when he suggested on Twitter that what he needs is a good dietician, or alternatively, a slot presenting “Come Dine with Me”.
Perhaps we need to look to the world of child psychology to discover clues as to why Chewy Luis had his Gnash of the Day.
According to the website zerotothree.org he “may lack the language skills necessary for expressing important needs like anger, frustration, and joy.”
The child psychologists suggest he may be overwhelmed by sounds, light or activity.
All that maudlin singing on the Kop is just too much.
Or perhaps he has a “need for more active playtime , is over-tired, or has a need for oral stimulation”.