Descripción de The Devil Bat:

Dr. Carruthers plots his revenge on his employers who are making a profit off of his invention. He electrically enlarges bats and sends them out to kill his employers' family by instilling in the bats a hatred for a particular perfume he has discovered, which he gets his victims to apply before going outdoors. Johnny Layton, a reporter, eventually figures out Carruthers is the killer. He puts the perfume on himself and Carruthers in the hopes he will reveal himself, but the bats swoop on in before he get a confession.