well, my friend has a V1 (i have V2 but my parents don't let me take it to school) and she takes it to school and during lunch, P.E. or free time, she starts playing with it.
It's a random animation.Many characters have their own special random animations.Bandai put this in so you cannot choose when to do its cartweels...so on...so on.
don't worry. if it's a marutchi, then it's part of it's personality... it happens to some other toddlers too... i suggest that you check the character chart