Anyone know what lives in these?

[Holy_makerel]

There are roughly 10 of these that are made everyday in my 29gal sandbed. Sand is about 1" deep. The old ones are abandoned. just wondering what's making them.

 

[Nibejeebies]

Critters.

No Srly though Ive seen pods burrowing from time to time that make these, as well as some tiny little other critters that I haven't been able to positively ID bit i know my fishy friends eat them to no ill effect so I assume they are beneficial

 

[Holy_makerel]

Critters.

No Srly though Ive seen pods burrowing from time to time that make these, as well as some tiny little other critters that I haven't been able to positively ID bit i know my fishy friends eat them to no ill effect so I assume they are beneficial

I figured they weren't detrimental. i've been calling them critters haha