BLUE TONGUE SKINKS

My bluey Mogwai just started trying to eat his substrate (cypress mulch, eco earth, and a bit of sphagnum moss). I quickly pulled the mulch out of his mouth carefully but now he's also rubbing his head on the substrate.

It would be pretty weird for them to actively try to eat that type of substrate. I would presume since he rubbed his head on the substrate after - that it could be from eating recently (trying to rub food off his face, accidentally getting it in his mouth..since they can be a bit clumsy, and not easy to get substrate out easily with their little feet!).

If however he wasn't fed recently - do you know if he is shedding? As similar to above, they may rub on things to try get the scales off. If you're able to provide something semi rough that could help out (and depending on your subspecies, keep a check on humidity). Edit: just seen your first post, did you get an ID for him?

Otherwise I'm not sure... I'm aware if they are actively trying to eat substrate it could be a sign of deficiencies in the diet, but I would presume in this case it's more of an accident than intentional. How long have you had your bluey/rough age? When we first got ours she struggled a little with using the substrate (accidentally would lick it when exploring), but now no problem at all.

He hadn't eaten yesterday, soon after he stopped and is burrowing. He is about 3-4 months old and he's a Meruake. And he's going to shed within the next week or so. Humidity and temperatures are fine. He probably just dropped a small piece of food on it the last time he ate and smelt it.

After observing similar behavior I have since been putting their food bowls on a paper towel. Haven't seen them try and eat that.