why are they doing this?

[SandyFeet]

Today my two neon gobies have started building a fort lol
I just noticed that they are moving sand from the back corner of the aquarium and piling it into a mound.

Is this just something that they do? or an indicator of something else?

 

[austinsdad]

You sure they're neon gobies?? I didn't know they moved sand.

 

[eric faatz]

my sleeper goby does the same thing...he scoops up sand in his mouth and dumps it into a pile.....i always thought it was normal for gobies

 

[cabezon]

Sleeper or sifter gobies eat food from the sand.