These are on the east side of the chasm, FYI.
Was just there to grab mandibular bite. Make sure you bring antidotes to cure their very nasty venom spit move if you're camping them.
Was lvl 44, they were always easy prey to me, giving me just shy of 50 exp.
Also, antlions are VERY SLOW. You can easily run away from them and lose sight of them. Even with my Slowga Galka rear.