Something freaky driving me crazy...
 

All right, I think I'm either losing my mind or something is seriously up with my tank. Every night at about the same time (10-11pm) while I sit and watch TV, I start hearing this scratching sound coming from my tank. It sounds like this grinding/scratching kinda noise. Whenever I look in the tank with a flashlight, I see nothing. I have always suspected some hidden critter in my tank since day one. When I first set up the 60g hex I would, almost daily, see long strips of what looked like fecal material collecting in a corner of the tank. After moving to the new tank, I found one again. Now I'm hearing all this scratching. Can anyone give me a clue as to what they think it might be? Here's some pictures of the pooh from the first tank:

have you tried waiting until the lights have been off for a few hours and then checking with a flashlight that is crazy about the scratching noise I have never heard anything like that before

When I hear it, the lights have been out for two hours or so. I have a blue LED for moonlight on the new tank. The lights in the room are still on, as well as the TV.

How would you describ the scratching sound?

My initial impression would be something scratching on the glass. The only thing I know of in the tank that could do that would be my trochus snails, maybe doing a 180 on the glass, but I doubt that's it.

any other sounds like clicking or knocking?

that must be a giant snail to leave a piece of poop that big :icon_lol:

That's just it, it's not really like scratching, it's more of a clacking. Hard to discribe, but very noticible when it happens. I'm sitting maybe 12 feet from the tank.

BTW, I'm up on AIM if anyone wants to chat.

At the time I took the original photos of the poop, there were no critters in the tank yet, just LR.

That is a rather large piece of fecal matter. I'm not sure what kind of hitchhiker it could be that would be big enough to leave that. Have you heard any popping sounds? Maybe the culprit could be a pistol shrimp or possibly even a mantis, but I'm not sure with poo that big.

There came a time where the pooh stopped appearing. It was after I added fish. I had completely forgotten about this until I moved everything to the new tank and found an even larger pooh laying on the sand one morning. I am still clueless as to what this can be, but I haven't lost any animals to it that I know of. One of the blue damsels that I had which eventually died had some visible damage around it's mouth the day before it died. I never really associated it with this mystery creature. I think the only way I will find this is to set up a night-scope camcorder or something.

This might be a stupid question, but are you sure that it is fecal matter and not a tube building worm?

I don't think so. When ever I would attempt to get the pooh out of the tank it would just disintegrate into the water. I'm pretty sure it's pooh.

So no popping sounds?
Good luck on figuring out what it is.

If you do happen to find it try and snap a pic. I'd like to know what it is. :)

same here... I was thinking along the line of mantis but since you haven't lost anything to it then I'm stumped...

Found more pooh today in the same general area as the last one. I'll post a pic later. This same activity happened in the 60g hex tank. The pooh would always appear in the exact same place in the tank. Each morning when I would check the tank I could count one new piece of pooh added to the pile. Today's is at least an inch long. I am baffled. I have asked people at the LFS', but everyone thinks I'm nuts.

If you really want to find out what it is then here is an invasive technique for you to try. This works well for mantis removal too.

Get some 1/4" or 1/2" nylon mesh screening and make a simple wood frame and staple the mesh to it. Pull the rocks out of the tank where you think the critter is and place the rocks on the mesh screening. Underneath the mesh place a tupperware container full of saltwater. Mist the rocks regularly with saltwater and a spray bottle to keep the bacteria and coraline alive. Eventually whatever critters are in the rocks should eventually seek the water and fall through the mesh into the container below. This could be a long process taking a day or two. Just an idea. The problem is that it requires you to remove the rocks from your tank which can be a bit invasive. Just throwing out a suggestion.

Well, today I found another dead hermit, so I wonder if these events are related. I have been occasionally finding hermit claws laying in the tank but always thought they were from a pair of hermits fighting it out for a shell.

Are you sure it is not a molt? Sometimes it can be difficult to tell the difference. Are you noticing less and less hermits in your tank? If so the may be killing each other. The solution to this is just to provide extra shells of varying sizes. Or maybe the mystery critter is a mantis who is snacking on your hermits?