Causing trouble (10)

'causing trouble' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for bothersome that I've seen before include "Trying" , "A pain" , "Annoying" , "Irritating" , "Perplexing" .)
(Other definitions for mischievous that I've seen before include "Playfully troublemaking" , "Naughty" , "full of monkey business" , "Impish" , "Spiteful" .)