Bats seem to target ppl doing healing aggro above anything else. When my guild was learning Tortos, as a guardian druid on bat tanking, I was having quite a bit of trouble picking up bats before they smacked someone. I noticed that they went after A) one of the 3 healers, or B) Tortos tank whenever he had used Enraged Regeneration. Finally, it clicked during an encounter when I used Tranq and the bats snapped to me (It had been over 30 attempts by this point) that I could try using Rejuvenation. I then found out that by having rejuve rolling on 3 targets, the bats would snap to me.
So, if all the above comments dont help, spec into that HoT heal and have 3-4 of em rolling on the raid when bats come out.
---------- Post added 2013-04-10 at 01:38 PM ----------