The significance of cats in Nosferatu

After watching the movie, i kept wondering why Robert Eggers decided to add cats in the movie. Both Ellen and Albin have pet cats, and Albin even comments on Ellen's cat, to which she replies her cat has no master.

I think the reason Eggers gave both Ellen and Albin cats is to signify their supernatural nature, Ellen literally being in tune with the supernatural while Albin is merely aware and understanding of it.

Obviously there's also Orlok who, on his arrival in Wisburg, brings the plague with him in the form of rats, and quickly infects the entire city. In medieval Europe, cats were often considered to be demonic or linked to witches. During this time they were persecuted and executed en masse, and it is believed that this is what caused the plague to spread. Without cats around to keep their numbers in check, mice and rats were allowed to breed and their numbers increased significantly.

At the end of the movie, Ellen "tricks" Orlok into drinking her blood, keeping him occupied long enough for the sun to rise and destroy him. We see here that the cat (Ellen) has succesfully captured and killed the rat (Orlok). The movie ends with Albin picking up Ellen's cat looking out of the window, knowing the plague will cease to exist with Orlok's destruction.

Anyway that's just my interpretation of it.