I'm talking about the Harley Heads in the Steel Mill where if you press the button, you hear Harley talking through the intercom. I know I have to do something to them, because there's a count for them in the Riddler's challenges under the Steel Mill, just like the Joker Balloons and TYGER cameras.
- pushing the button several times, but it just seems to annoy her
- using the explosive gel, but doing so makes him use it on the wall behind the head, which does nothing
- trying to use the various Batarangs at my disposal, but there's no targeting reticule for them
What do I need to do to destroy these?