Chasing Invisible Mice

Picture of Invisible mice

I am a little worried about my cat. She will occasionally (seemingly unprovoked) run around the apartment with her crazy eyes as though she is chasing a toy or something that isn't there.

She'll also paw under the couch as if there is a toy stuck under there even though there is not. We just moved to a new place and I'm worried that the change is stressing her out.

I'm especially worried for a couple of reasons: She's been having issues with urinary tract infections and I have heard that stress (such as that associated with a move) can trigger UTIs.

And also, a previous cat of mine used to do the same thing and started doing it more frequently right before she died (I'm concerned that it is an indicator of poor health).