Aiyoh, normal je lah, most toddlers go through this phase, don't worry! At 2 years old, they're exploring their bodies and testing what feels good, plus sometimes it's just boredom or they're trying to soothe themselves (like when they're tired or anxious). A few of us mums notice our kids do this more when they need a snack, need the loo, or getting a bit restless, so sometimes it helps to keep them engaged with activities or check if they're uncomfortable lor.