I recently added two scissortail dartfish and i guess they're still scared and not used to the tank so they seem to enjoy hiding in the cave when im in the room, but if i hide or exit the room they come out and swim. Sometimes i get worried and check in the cave with a flashlight to see if they're ok. The aquarium lights were off for about an hour and i checked inside the cave with the flashlight and i noticed an enormous bristleworm the thickness of a pencil. The light scared it and it began to slide into a rock. I kept watching it, it kept sliding and sliding, almost for 15 seconds this thing kept sliding, just like watching a long line of railcars at the railroad crossing. To me this means that the worm is huge. My concern is that the worm is in the same cave as the dartfish. Its been about 2 hours since i noticed him and my dartfish are NOT in the cave and no where to be found anywhere in the tank. Well have to wait till tomorrow to see if the dartfish are ok, but what can i do to hunt down and destroy the bristeworm. Sorry if this paragraph is too long, i like to be thorough.