Fans of Bela Lugosi will not want to miss this one. Instead of playing a vampire, he plays a "mad scientist" who experiments with bats. [A little bit of type casting here?] Lugosi is Dr. Carruthers in an old fashioned tale of revenge. He's miffed because the products he invented made his employer rich but not him. So, he cooks up a scheme to get even that involves giants bats and a new after shave they are particularly attracted to. I'm sure you can imagine where it goes from there!
The unintentionally laughable scenes in the film occur when the bats leave Dr. Carruthers laboratory. The director uses the same footage over and over and over again. This also happens when the bats are flying in the air. I guess they hope we won't notice! Oops!
The movie is well acted by everyone and is nicely filmed. The plot is well thought out and the characters are believable. It's not a "magnum opus" by any stretch of the imagination. However, it is an enjoyable film to watch. You can watch it for free on may internet sites.
Download a copy of the film from Archive.org
For more info check out the film's entry in IMDB.