I took a quick look at your previous posts, and it seems like Barney is just more used to making noise to get you attention. It’s probably something he learned helped to do before you rescued him.

Ignoring him is fine if it’s a bad behavior you don’t want, but are you sure there isn’t something important (to him) that he really wants you to notice so he continues? I would examine him and his habitat carefully. There may be a dirty litter pan, or something in his water, or another thing that may seem small but is bothering him. See if he acts up around anything that may lead you to notice what it could be.

And yes, if it’s just a way to get you to pet him, then pet him a lot when he’s quiet, and not at all when he thumps. Just want to rule out a genuine complaint first. (I get odd behavior when I say “I’ll clean the litter box in the morning, I promise.” Not soon enough for Herself, sometimes.

I remember when Bindi was in a plastic bottomed cage! Those thumps are super loud! Bindi has now resorted to digging in the corner when he wants something and I don’t know what else to do so I TRY to ignore but it’s so hard.