Spiny peacock eel

[cmaly]

My spiny eel (FRED) has been acting strange lately, ive had him almost a year now. First week was normal from what i read, shy and not eating. After he got used to all his tankmates he was pretty active, didnt burrow as much as i read. For the last 2 weeks now he has been burrowing constantly and hasn't even come out to eat for the last 2 feedings. Any idea as to why he would be acting this way?

 

[Delapool]

I can't think of anything off-hand but have never kept them. Checked your water chemistry?