うろちょろ
urochoro

Suru Verb
To-Adverb

1. hanging around; wandering around (aimlessly); moving around (restlessly); running around

Onomatopoeia
電車 でんしゃ なか子供 こどもがウロチョロしていて 愉快 ゆかいだった。
denshano nakao kodomoga urochoro shite ite fuyukaidatta.
I felt uncomfortable with those kids loitering around in the train.
Other forms: