I didn't see this film, but the title seems good: The Vampire Bat. Vampire film! The film directed by Frank R. Strayer, that made other horror films, has Fay Wray, Melvyn Douglas and Lionel Atwill. It's available for free on Internet Archive and can be downloaded here.

PS.: if you like Fay Wray films try The Fay Wray Pages, a homage site with biography, pictures, lobby cards, posters, audio and filmography.