Anak ko, yan ay very common sa age na yan! Most toddlers do this kasi they're learning to self-soothe or sometimes it's just their way of blocking out stimuli before sleep, a few of us moms noticed it din sa aming kids around that age. Normal lang talaga, but if it seems excessive or parang anxious siya or may skin irritation from it, it's worth checking with your pedia just to be sure lahat okay lang. Mine outgrew it after a few months, so don't worry too much mama!