Are these a good type of pod?

[rickyljones09]

I'm having a hard time identifying these, can anyone help? Good or bad? They are crawling all over my sand bed but don't seem to be doing any harm. Thanks!

 

[Spare time]

I think that is an ostracod? If so, they are fine

 

[rickyljones09]

I think that is an ostracod? If so, they are fine

I think you're right. Thank you.