Sentimental Sunday, The Hero Was a Mischievous Boy

A story the Hero would often tell to remind himself of how boys are not always angels, was one between his mother and himself at about age 6.
It was a beautiful day for being outside.  The Hero had been playing in the backyard, but soon ventured into the front yard. After a little, he wandered across the street to the neighbor's yard.  After a while, he heard his mother calling his name.  Did he respond?  No, he shimmied up the front live oak tree.  Climbing up as high as he could to keep from being seen.
Soon, he saw his mother come out into the front yard calling his name and looking for him.  He said, "I don't know why, but I scrunched down more into the branches and didn't say a word."  She then came across the street and knocked on the neighbor's door.  He heard her ask if the neighbor had seen him.  They walked out right under the tree where he was and started looking up and down the street.
At this point, he was thinking it was funny they didn't see him, and began to snicker.  He couldn't hold it back, one snicker turned into full blown giggle.  His mom looked up and there he was...   We are left in the dark at this point, because he said, he didn't remember what happened after she found him.
What do you think happened?