A new study says 66% of parents fib to their kids. And you won't believe the reasons why!

•If you twist your face like that, it'll get stuck.

•Sitting in front of the television for hours gives you square eyes.

•Santa only gives presents to good children.

Of all the lies we tell to our kids -- and 66% of parents do -- which is the most common?

A new survey of 3,000 moms and dads found parents fib to get some much-needed peace and quiet, while others do so to encourage their kids to behave. Eight in ten parents say they often lie to protect kids from the truth. And a guilty 46% lie if they don't know the real answer to their kid's question.

The study, commissioned by The Baby Website, also found that our lies have their roots in history: The lies we tell our kids are the ones our grandparents told our parents. In fact, the average parent tells their child a little white lie every single day.

•Santa only gives presents to good children -- and ones who go to bed early.
•Spinach gives you big muscles.
•The jingle of an ice cream van means it has sold out.
•If you eat the apple core, an apple tree will grow in your tummy.
•The police arrest children who swear.

And the lies work! According to the results, kids absorb everything, with 57% repeating lies to teachers, friends -- even family members.

But no need to feel too guilty -- the majority of parents agree their kids usually stopped believing everything they were told without question by their eighth birthday.

What do you lie to your kids about?