User blog comment:Jojo-a-gogo/Do you guys ever wonder why Hisoka wasn't in the Ant arc?/@comment-48285-20130105182229

Well, there are plenty of reasons why Hisoka wasn't in the Ant Arc. First off, he had to deliver the Nen remover guy to Chrollo so they could... um... do whatever it was that Hisoka wanted to do (really, his motives are just too vague. Is he using double-entendres?). And while he's busy doing that, he's miles away (I'm assuming) from the NGL so he doesn't know what's going on. Plus, there's no way the Chairman would let him in on what's going on even if there was a way HIsoka could contact him. Same goes for Gon and Killua, they'd never tell him.

When some of the Ants move away (I can't remember where they all go; I just remember the one going to Meteor City-so that's the one I'm going to use) and end up in Meteor City, he wasn't part of the Troupe anymore so they wouldn't contact him. So, really, he was just in the wrong place at the right time.