Came home from work today and stopped to check the tank as I always do and found a perfectly symmetrical pile of sand about 4" in diameter with a perfect little circle depression around it. The depression is obviously the source of the sand forming the hill.
Any idea what could have made this? I thought about taking a deli cup and scooping the whole thing up and sifting through it but I don't want to disturb it if it's something cool.
Any idea what could have made this? I thought about taking a deli cup and scooping the whole thing up and sifting through it but I don't want to disturb it if it's something cool.



