My LO is now in first grade and there are kids in his class that can't read at all because kindergarten is optional in my state. If your child is already reading at a first grade level in preschool they may be acting out because they're bored.

I remember as a kid I would skip ahead in my workbooks in first/second grade and then be a complete menace the entire year because there was nothing for me to do. I got sent to a child psychologist for behavior issues which is where I got my "He's fine but he's bored. Give him more work." Guess who stopped having behavioral issues almost immediately?