what makes sand mounds?

[escape2thewater]

I only have a very small piece of LR in my tank now as im waiting for my sandstorm to settle. Everyday it gets more clear but tonight I noticed a small sand mound a few inches from the rock. Its about 3/4" tall and 2' around, looks like an ant hill and has a small, white worm looking thing that comes out of the center every once in awhile. The rock was in a LFS tank for a couple months so its very cured. any ideas?
Thanks,
Kyle

 

[escape2thewater]

Ill try to post a pic but my water is still pretty cloudy - a little too cloudy for my POS digital cam but here it goes....

 

[nacl-man]

It is most likely just collecting there because of water currents. Do you have a powerhead or anything else moving water in there?
My Clarkii likes to dig... but it doesn't seem like you have any fish in there yet
Cheers!

 

[bang guy]

Probably a sessile snail like a Vermitid or some type of worm. It's just cleaning your sand for you.

 

[escape2thewater]

Thanks!

 

[joker]

I got tons of "worms" like that and they mound. consider it a good sign IMO.