Weird mouse poop?

So I brought home some feeders today, as my litter are still babies :D but I looked in the feeders tank and I found these long thick pieces of something in their tank :s

Here's a picture. It's hard to explain

http://img.tapatalk.com/d179e1f4-96dc-eee5.jpg


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I am here: http://tapatalk.com/map.php?czyl11

Looks like mouse poo that has absorbed some spilled water from the bottle.

Okay Ty :) I just wasn't too sure haha