To get back to the zoologically and anthropologically relevant information though, it is important to successfully distinguish between P. Sapiens and D. Horribilis so that you know which one of the two it is that will invite you to a party and which would like to suck your blood.
Basically, P. Sapiens are a primitive and overall alcoholic but agrarian culture that is for the most part content to live just in the Vupa system. At least some of what we hear in our ears to be those horrible shrieks at night and in some of the caves are really just how these bat-people communicate, using a form of echolocation.
They were in the process of negotiating a tense treaty with their carnivorous neighbor species over which tribes of each was allowed access to which caves and who would live in each region when the activities of Herod and Mad Mulligan disrupted it all.
The societies of each are tribal and have a rudimentary economy based on a bartering system. While aware of other species and that some civilizations have technological capability for space travel, the bat-people tend to prefer staying put on Vupa. They aren't interested in other parts of the galaxy. They don't mind trading with those other civilizations though and the main export are their many liquors. It is typically quite difficult for humans to understand either species' spoken language but generally trade can be conducted through drawing pictures and with physical gestures. Trade with P. Sapiens is safe but doing business with D. horribilis (the more barbaric of the two) is ill-advised.
Disclaimer: Vupan whiskey is quite strong for humans to drink when it is undiluted. Bat-people possess an altogether different physiology to their metabolism than human beings so their bodies are a good deal more tolerant to alcohol than ours.
Submitted by Mycobacter#712744