I purchased a Nestcam last month because of all the travel I have for the month of May. It was super easy to set up and I have not experienced any problems; it sends you a notification through your phone app when it a person is detected as well as if there is "activity" -- this has been my birds moving around their cages, sunlight moving across the room, and even lightning outside the windows. When I was on vacation, I used the microphone to talk to my birds too (and you can listen too). In addition to the app notices, I also get notices when the camera is off -- these were not long periods of time, but because of my internet connection, it would happen on a few occasions. My Nestcam does not swivel or pan, but I have it sitting on shelf that is eye level to the cages.
The Nestcam is on the expensive side, though, and when I was doing my research, I was also interested in the camera that
@Dartman listed and the Amazon version:
Amazon Cloud Cam Indoor Security Camera, works with Alexa Ultimately, my laziness gave out because of everyone who told me that they loved their Nestcam and me not wanting the hassle of testing out other cameras.