" what does bat poop/pee look like? and would they congregate in a tree in a pretty busy neighborhood? "
pee is usually clear. as mega bats digest very quickly and absorb as much as poss.
poo depends on what they are eating. example, yellow (light n dark) to very black, runny and smelly.
black and very smelly could be due to palm tree seeds. most palm's were introduced by humans and are considered as a weed. cocos palm is the worst.
providing this food source, the bats now get blamed.
usually mega bats will poo immediately if scared or stressed out of a tree. hence the poo on fences, roof.
bats prefer to poo/wee hanging in a tree by thumbs/arms. not in flight.
yes, they will group together. a camp is usually near water/creek. a group away from camp could be in a tree that is proving a food source or they are resting when on the move.
bats have been in a busy neighborhood for a very long time.
neighborhood's/towns have been built around bats.
a camp, has most likely been used for >1000's of years. depending on the season/environment, different camps are used.