An curved arrow pointing right. A popular illusion online has people scratching their heads. The trick involves taking one giant chocolate bar, cutting it into pieces, and shifting them around ...

An curved arrow pointing right. A popular illusion online has started to make the rounds again on Facebook, and it has people scratching their hands. The trick involves taking one giant chocolate ...

While dogs and babies are ripe for the optical illusion trick, it seems a load of grown-ups are getting in on the action, too. All you need to take part is a plump slice of the pink stuff ...