I lived a number of years in Austin, Texas, where they have a large and
world famous bat population, but in all that time, I never once heard of
bats getting into people's houses.  I guess it could and has happened,
but it never got much publicity.
 
It sounds like the apartment people were just giving you the brush off
and making excuses.  If they used the right screen, there IS a way to
solve that problem and not create a fire hazard.  Rabbit wire comes to
mind, and if that wouldn't work, there are several sizes of chicken wire.
The holes are plenty big enough to not get clogged, but small enough that
no bat could possibly get through.  It can be easily formed, and with
enough surface area, there's no way it could get clogged.
 
If it were *me*, I would have gotten some and formed a decent size wire
"cap" and attached it to the ceiling over the bathroom fan.  That way, it
could easily be monitored for getting clogged.
 
Apartment managers are notorious for doing as little as possible to make
things right.  They failed to take into consideration that a dead bat
stuck in the fan could also cause an overload and a fire.
 
Gary
[Posted in FML issue 4301]