Cockroach

I had some difficulty at first finding the cockroahces in Icecrown as well, but there are tons of them. They seem to spawn in a very spread out manner. The best method I've found is to fly around the main "horseshoe" shaped area along the edges where the ice cracks apart against the mountains. By the time you do a full lap of the outer and inner edges of the horseshoe, the ones where you started will have respawned already. Visit Ymirheim and the Nerubian place if they get too thinned out.

Can also be found as a primary & secondary in the Wetlands, either northwest of the Greenwarden's Grove amongst the Tiny Bog Beasts or east of Greenwarden's Grove.

There are a bunch of Cockroaches in The Hinterlands in Jintha'Alor. Some are in odd areas that obstruct the battle, but I was able to get mine here.

Cakebaker was asking about Cockroaches in Icecrown.Sorry to inform the other posters but the Hinterlands is not in Northrend so their postings are useless.I also can't seem to find any Cockroaches in Icecrown,yet.I too am trying to find these for the Achievement.

Found the cockroaches at Ymirheim.I hope this Helps.

I want the northrend tamer achievement and only have Icecrown left on my list. However, I cant seem to get my hands on a Scourged Whelpling, so I'm trying to find a cockroach from Icecrown but they seem so few and far between.

Found my cockroach in Hinterlands.  Didn't see any roaming around, but were the second when battling hares and jade oozelings.  If you see one appear as a second go ahead and grab it.  Marmots, hares and oozelings are plentiful, but couldn't find any lone cockroaches myself.