Is it seen as bullying when someone pulls pranks on someone else?

It depends on what kind of pranks they are and how often the person does it. If they are joke pranks that are meant just as a joke and the person being played on knows it is a joke and dosent mind-then it is not bullying. If it is a very mean prank and the person doesnt like it, and it is done continuosly, then it could be bullying.

For example:

Jenny and her friends steal Mary's art pens every single time Mary has an Art period. She gets in trouble and that is what they want. She even gets detention and she hates it but they just tease her when she asks them for the pens. One day Jenny broke the pens on purpose.-----This is bullying. Its a very mild case of bullying-especially compared to what some people get- but its still bullying.

Taylor and her friends decide to steal Jazz's art pens one day just for a lesson. JAzz knows it was a joke and they later give the pens back. This isn't bullying-its just a joke

Tip: If you plan to do a prank to somebody as a joke-make sure to do one that they will know is a joke. Sometimes people do pranks as a joke but the victim dosent realise its a joke, and they get hurt. Make sure its one that wont hurt them.

Being that appropriate time of year at present, If the prank occurred on April Fool's Day, I wouldn't take it too much 'to heart'LOL!