They're Legitimately Bored by the Subject
If all you hear when you pick them up from the bus stop is how bored they get in class, that may be a sign they aren't getting everything they need out of their classroom experiences. It's no surprise that it's the most common reason kids aren't challenged in the classroom.
And while it's safe to assume any grade-school-aged kid is going to complain about their day-to-day doldrums, if you start to notice a pattern, try shifting the conversation to one that's more productive.
Start by asking your kid to list what they find interesting when they're sitting at their desk (it could be anything from a favorite subject to a teacher) and what they wish wasn't part of their day. Once you get their feedback, see if you can set up a time to talk with their teacher to see how you can work together to make learning more exciting for them.
And if the pattern persists, don't take it lightly. "Children are naturally excited about learning, and it's important to pay attention if yours is bored in school," said family therapist Alison Ehara-Brown in an interview with BabyCenter.