Which exhibit were these in? I'm surprised you managed to get so close to so many bats - in my experience they've either been quite far in the walkthrough enclosures, or they've been near the path but the enclosures were closed.
These and the Rousettus (whatever they are) were both in the Malaysian Lowland Forest "aviary" which is now open to walk through - it was locked up on my last visit - and they were all roosting in the roof part of the visitor area.
The Large Flying Foxes were in the Milky Stork aviary which is still locked up but the bats are easily visible (I didn't take any photos of those though).
