What are these tentacle things?

[Tomo]

In my sand there are these little mounds and every once in a while a clear "tentacle" comes out of the mound and seems to search around it's area. Sometimes the mound has two or three of these tentacles. Anyone know what these are? There is no way I can get a picture as they are pretty small.

Thanks,
Tomo

 

[kfisc]

There are a number of creatures that somewhat fit that description; many are beneficial, so unless you see evidence of it irritating another inhabitant, nothing to worry about.