Thanks for the reply, 1beataway

I figured it was something of the sort, although I wanted to hear feedback on the subject. Yes, I probably need to invest more time in interacting with him (although he spends a lot of his time submerged in the substrate and I in class). Still, I've made progress: he lets me stroke his back with my index finger, and today, I was able to brush most of the soil off of him to get him looking clean and photo-ready