Okay, that makes sense about trying to feed too often. I thought he was hungry because he did seem interested every time I offered, struck and coiled once, and he comes out to "hunt" at night time which he usually doesn't do and that was before I began covering the fourth/front side. I usually give them all a day/night cycle and I know that's important, the only reason I covered the front is because I was thinking maybe he's not eating due to stress and seeing us walking by every once in a while could be stressing him out? Unfortunately I live in an apartment and there's only the one room large enough to fit the snakes, so I can't move them to an area with "less traffic" because there is no such area in our apartment.

Yes, I did mean thermostat, I'm using an exoterra one with the probe placed underneath the tub but on top of the heat mat. As of right now, I'm still just using paper towels as a substrate (I sometimes find him hiding underneath the paper towels) although I did purchase and have exoterra cocohusk. He usually spends his time about evenly between the cool and warm hides but it seems recently he's more often on the warm side. I just checked right now and the cool side is 75 degrees Fahrenheit, and the warm side is 89 degrees Fahrenheit. He was actually hiding in one of the paper towel rolls on the warm side. I know ideally the cool side should be a bit warmer, and I tried to do so by using insulation on three of the four sides surrounding his enclosure but it seems I can't get warmer than 75. The heat mat is 1/3 the size of the enclosure. He is on the bottom shelf though.

According to a digital thermometer and hygrometer I have, the humidity is 66% and the ambient temp is 74 degrees Fahrenheit. Again, a little low but I don't know how to get it any warmer. I even have the entire thermostat for our apartment set to 24 degrees Celsius (75.2 degrees Fahrenheit) all the time to try and help. But all of these have been the temps ever since I've had him, they haven't changed and he used to eat just fine. The other snakes all eat just fine as well with the same temps (only slightly different due to shelf placement, like top shelf is slightly warmer than bottom).

So maybe like you said, after eating that huge 38g rat he was just really stuffed and doesn't want anything for a while. If I do switch to offering every other week, what size do you think I should offer? Just the same size as his girth? Or should it be a little bigger than usual since he'll be eating less often?

Btw I do increase the humidity when I see that they are going into shed. I put the water bowl on the warm side and spray with a misting spray bottle.