Why kid lies?

Yesterday evening, I fetched my little than than after natnat as usual. Suddenly natnat made a 'lion' roar at me. I was mad, immediately I told her that she had to pull her ears three times when we reached home. She begged me not to punish her, then I asked her why did she act like that. She said, "I don't know." Then I told her to that I will add another 3 times pulling ears on her. Guess what? She said, "I know because you carry than than. Now, I don't need to pull ears, ok?"
SO KID LIES BECAUSE OF JEOLOUSY! She is jeolous of the younger brother who is only 5 months old!

This afternoon, before I left for babysitter's house, I asked her whether she has locked the door of the master bedroom (I am scared of lizards entering my room!). Again, she said 'No', then immediately she changed to 'Yes'. SO KID LIES BECAUSE OF LAZINESS! This time I didn't punish her anymore, in fact i didn't punish her too yesterday. I told her that I knew she lied and I forgave. Then I asked her to go upstair to close the door and I will give her a big kiss and hug after that. So she walked with her two stumpy legs slowly upstairs and came down steadily with the door closed properly. Of course I gave her my most sincerest kiss and hug, and she kissed and hugged me too.

She is only 3 years and 1 month, she has a long way to put her integrity right.