mischief/mischievousness (noun) – naughty or playful behaviour that can annoy other people

mischievous (adjective) – naughty or playful in a way that can annoy other people

mischievously (adverb) – in a naughty or playful way that can annoy other people

Sequola Hughes

Who do you think will be more mischievous: the pelican or the child?

Examples:

Let me check whether the children aren’t up to any mischief.

I put the fence in the hallway to prevent the dogs from engaging in mischief in the kitchen.

Oops, that police officer is signalling us to pull over. Now try not to cause any more mischief.

The young teacher found it difficult to deal with the pupils’ mischievousness.

– Why do you have that funny extra corner in your dining room? – I have no idea; looks like it was some mischievous idea that the architect put in to amuse herself.

He had a mischievous grin on his face as if to say: Looks who’s being clever now.

Her eyes were twinkling mischievously as she told a white lie.