White substance around tarantula's mouth

[goldenpumpkin]

Apologies if the pic quality is not good enough, but this was the best I could get. So I noticed this white stuff around my mature male's mouth not long after he ate and I am wondering if it is anything I need to be concerned about, seeing as how I have had him for over 2 years now and I've never seen this on him before. For context, no it does not have anything to do with his missing fang, because that fang broke off about 2 years ago. From the info I could find from research, other people have said white stuff around the mouth could either be nematodes or even poop. To me it looks like dried tarantula poop but I don't understand why he would be eating his own poop. It's not from drinking out of a poopy water dish because he actually does not poop in his water dish lol. Also, his behavior has remained exactly the same and not changed at all. The substance is not liquidy; it is crusty looking.

Thank you to anyone who can help