I think they do it to harden their feces but im not sure or i think it means they need more vitamins in their diet as they eat the dirt to gain some minerals
my gf is having a major problem with her 5.5 month old male veiled. he loves dirt! i would think they sometimes would do it for a mineral/vitamin solution, but than again... does coco husks have vitamins in it? lol also.. perhaps it helps with digestion? or maybe their just fat and want extra treats lol. who knows, but if they do it alot, i would switch the substrate to a terrarium carpet for a little bit to stray away from possible impaction
i know exactly why they eat dirt, I mean have you ever tasted it? Its some pretty good stuff. It makes a pretty good dessert after eating bugs as well, mudcake, u may have tried it before. Hahaha couldnt resist. My Carmie was eating dirt too so i covered it up with river rocks.
IMHO the biggest concern with them eating soil is whether or not it will cause them to become impacted....and you're not going to find out that the soil causes that until it happens. That's why people are concerned about it.
My thought is this.....my panther would seek dirt in his younger days. I mean if he saw a plant while he was out free ranging he would do anything it took to get to that dirt. I let him eat it since I knew it was clean and I figured he knew why he was doing it. Now since he is an adult, I've never seen him eat dirt. The best advice I can think of is make sure any dirt they have access to is free of pebbles, insecticide, fertilizer, etc.
if people are concerned about their chams eatin dirt/substrate incase of impactation i would take the substrate out and use nothing and cover the dirt up in the potted plants jmo though ive never experianced this with my chams
Thus far, my new guy, Lloyd, has avoided dirt (knock on wood), but there's apparently something he finds irresistably delicious about dead leaves and sticks. He sees one and he wants it. I was able to get the stick away from him before either could do any damage to the other, and he doesn't have a chance at toxic leaves, but I'll be keeping my eye on him. I fail to see the allure, somehow.