Lox used to only aggro at point blank range, but they are smart and after being farmed for a year by hungry vikings, have become hostile.
they are hard to deal with. Get 3 of them on you and run, they destroy every tree, building, rock, etc that you try to run through and it barely slows them. Getting out of LOS Is tricky when they wipe out all the obstacles! Terrain exploits work if you can get out of reach up a slope they can't climb, then get behind an obstacle they can't reach and sneak, they will go away. Otherwise, just kill them for food, though I admit that 3 at a time can be more trouble than worth.