There are two common species of bat in Massachusetts (little brown myotis and big brown bat) and a handful of less common ones. The former two are widespread and are plentiful in many areas around Massachusetts, urban areas included. They're still common, but our bat populations are generally declining due to a fungal infection called White Nose Syndrome that infects hibernacula (the caves where bats spend the winter) and interferes with their hibernation, causing them to wake up and become active when there is no food, leading to starvation.