Ostracods? Good or bad?

I discovered tiny circular organisms in one of betta tanks. They seem to be living in thesandand on the plants. Teeny little dots! Tried to photograph but the best my phone can do is a gray blur. Are they good orbad? Saw a cherry shrimp eat one so I'm inclined to think they are a weird extra food source...but does anyone know if they harmfish shrimp or snails?

 

They look like a seed? Small round and plump? Or they elongated

 

Small round and plump, can't see their legs but they are clearly moving on my plants like teensy aphids so mobile somehow.

 

Water lice. They're fine. They infest the water column. Ive had them in my old tank for years. Along with limpets. I actually want some

 

Thanks! Curious now why do you want some? If I hadn't been intently watching my tiny baby snail I'm not sure I would have noticed them

 

Water lice are signs of life in an aquarium. Means the tank has happy and can support microorganisms. Means they're eating something. And fry will consume water lice babies and other fauna