What happened to the trick-or-treating?

All my 4 kids don't trick or treat properly anymore, Martin is the worst, he keeps standing by the graveyard like he's waiting for death or something and now my snarling zombie doesn't stay on the pavement like he used to, he keeps roaming off into green lands and woods which makes it a pain to find him......only reason I try finding him us because I keep thinking he's gone missing.