Farming Crippled Again?

I have been vermin farming with my rit, but when the vermin get low health, they just run away, sometimes they just stand at a distance and not move when I come around, even when i attack them. Is there a reason for this? I am guessing Anet nerfed farming again.

Anyways, I thought aoe cripple was enough, but now this? Comeon -.-

What I have noticed is three at a time attack you no matter what, unless your using AoE skills to kill them. If your using single skills to kill one at a time, then you will be able to kill them. Slowly but surely it will happen. Instead of cripple. Try using like Frozen Burst, or another ele skill to snare them.

Been that way for a while, monsters run away to heal for a bit if you hurt them to badly and they aren't your immediate target (ie you're hitting them with aoe, but you're not wanding them)

It's been that way since just before the release of Nightfall.

If any more than 3 melee monsters are attacking you, once they get to about 1/4 health, all but 3 of them will run away (it sometimes depends, I've noticed that occasionally sometimes no more than 3 will attack me regardless of their health, and other times all will until they're down to 1/4 health). Any monster that you're physically attacking will not run away as long as you're attacking it.

I farm vermins sometimes with my warrior using that Triple Chop build. I've noticed that the vermin do run away but I still don't have problems killing them. It just takes maybe 30 seconds longer or w/e for the stragglers to die.