My adorable, doe-eyed daughter — the same sweat pea that greets me every morning with, “Good morning mommy! I missed you!” and every night stretches her arms wide open and says, “I love you THIS much” — has recently picked up a new, less charming habit.

Lying.

It started innocently enough, telling her daddy his parents had stopped by for a visit or that her and mommy went to the playground, when neither were true. But since those are regular occurrences, we thought maybe she was just confusing her days.

Over the next several weeks, her tales grew taller.

One day she told daddy all about the fishing trip we took, and the big fish she caught. A few days later she proudly told him she had gone on the potty, and was receiving accolades when I had to break the news that she was fibbing. And then she argued with me! “Ava, tell the truth, you didn’t go on the potty.’ “YES I DID GO ON POTTY!” Err. The teen years flashed before me.

When she got busted jumping on the couch, she assured me it wasn’t her, it was her friend Katelyn. Of course, Katelyn wasn’t even at the house.

Apparently that’s a common toddler fib. My friend’s 2-year-old frequently blames her older brother for pushing her down, despite the fact that he’s at school.

And I can’t tell you the times poor Barney, Mickey and the family pet get the blame in toddler homes everywhere.

When my friend’s 20-month-old son had obviously soiled his diaper, prompting his dad to ask, “Did you poop?” he replied with feeling, “Oh NO daddy not me! Barney poop in my diaper.”

Those self-serving fibs are among the earliest our children tell, usually to avoid something — like the dreaded diaper change — or to gain something, maybe that extra cookie.

Child psychologists say these types of fibs are perfectly normal and innocent at this age. Out little ones aren’t intentionally trying to trick us, they just can’t quite distinguish between fantasy and reality. Instead, the lies are usually based on active imaginations — don’t all children have dinosaurs living in their back yards? Or simple forgetfulness — he really doesn’t remember dumping juice in the car seat.

It’s around age 3 to 4 that most children begin to understand a purposeful lie — and they can tell some whoppers — but according to child psychologists that doesn’t mean they’re becoming pathological.

Those pre-school years are the times of imaginary friends, wishful thinking, learning to tell the difference between fiction and reality and just plain thinking it’s funny to fool mommy and daddy.

My friend’s 4-year-old daughter, refusing to go to sleep one recent night, explained that she couldn’t go to sleep because she had to write an essay.

Another friend recalled calling the fire department when she was 5, telling the horrified operators that her house and her arm were on fire. She then explained that Teddy Ruxpin made her do it because they were bored.

One of the funniest stories I heard was on “The Today Show” a few months ago, when a mom shared the story her 4-year-old told her as she was trying on lingerie in a department store. “Daddy puts on your bras sometimes,” her daughter said innocently. She went on in detail to explain that when mommy was asleep on Saturday mornings, daddy would put on the bra over his T-shirt and then jump on the trampoline.

Instead of making an appointment with a child psychiatrist if your toddler is becoming an adept liar, consider this: Research shows that preschoolers with higher IQs are more likely to lie and early lying may be the predecessor to good social skills.

So the next time your little one tells you his teddy bear peed on the floor, just start calculating that college scholarship money.