For the past 3 weeks I've noticed my blenny would not come out of his cave AT ALL. I would have to put food infront of him and maybe after 10 minutes he would go for it which is rare for him. just today when I fed him I swear I saw the front end of a bristle worm stick out of his cave but unsure since he has no bristles on him and still feels comfortable going all the way back to his cave. What should I do since I can't tell if he's malnourished since only his head pops out but he is definelty stressed and if they're is a bristle worm in with him would it be the thing causing these issues?