No, it wasn't his own blood. It was the blood of spiders that he was currently enjoying. These bats made up of his skill were practically dimensional transporter that was connected to his mouth.
Yes, anything and everything these bats ate or drank would be directly transported to his mouth.
This was an incredible skill, other than the fact that the duplicates were three times weaker, since the leader of the bats didn't even have to do anything on his own. He could just sit and hide somewhere and ask his duplicates to go and hunt or drink blood.
This way, there wouldn't even be a chance of betrayal since all of them are duplicates. Plus, the chance of his life being in danger was almost zero – but it wasn't zero!
Yes, all of a sudden, all the bats disappeared and the bat leader had a horrified expression.