Pits In The Sand?

[Ashy_]

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[dthoffsett]

Probably the start of breeding pits, it takes them quite awhile to excavate, they use both their mouths to scoop the sand up and they'll also push it around with their bodies.

 

[Abyss]

Breeding pits.

They can make HUGE ones in the wild.

Looks like your males are going to be getting frisky soon.