Yes he is alone, he has 40 gal. tank. Here is his setup:
We do have a cat in the house but she doesn't bother him, there's also no way for her to reach him
.<<<< looking at his tank, it is definitely NOT CAT PROOFED and cats can often get to places you never thought they would , expecially if it's determined to get there.... I HIGHLY RECOMMEND you take URGENT steps to make the tank TOTALLY CAT PROOF
(not a mesh top , I recommend a heavy timber top made from either solid timber (plywood) or from MDF that's got beading around the edge to stop puss from pushing it off , your local hardware shop's trade desk can arrange to have the lid cut to size and holes cut to allow the lights to shine through)
i'd securely fasten the domes to the new lid as well as a cat will move them to gain access to your beardie ---- this is only a matter of time. I had recently moved the heat light, it was much closer. I think the heat light loosened and moved downward while I was gone
,<<<< the odds are the cat has been at it while you were out.
he could pretty much stand up and put his head inside of it.