Dear WW: Bloodsucking is just a small part of nastiness of vampire bats. Far worse is the fact
that they are probably biggest reservoir of rabies. And insectivorous bats who share caves
with them pick up the virus in winter and in spring bring virus North. Although now there is
so much rabies in racoons that bat vectors are no longer important. I have read it is possible
to contract rabies just from exploring caves in Mexico.