In Patch 3.0.2, all bats now have Sonic Blast as their unique, bat-exclusive ability. It's a 2 second stun with negligible damage on a one-minute cooldown. As far as Hunter pet abilities go, Sonic Blast is pretty run-of-the-mill and isn't significantly great to merit taming a bat for. It pales in comparison to the Ravage skill of Ravagers, for example, which is on a 40-second cooldown. Ravage is melee range ability while Sonic Blast has 20 yards -- an irrelevant bonus considering our pets are almost always at melee range. It's only a little better for chasing and stunning, but otherwise, I would much rather have it available every 40 seconds than have some extra range.