Small bugs in my shrimp aquarium

[Humansulfide]

Hello. Recently I've been noticing small brown bugs in my shrimp aquarium. I'm pretty new to this new hobby, and I'm kind of worried about those bugs. I couldn't find anything about those small bugs. They're pretty quick and are maybe 2-3 millimetres big. They are light brown and have small stripes on them (?) And they eat things. Recently when one of my shrimp passed away they started feasting on it. I don't know what they are and they might be distressing my cherry shrimp.. I have a 50 liter tank with around 20-30 shrimp.
The shrimp that have been passing have always been slightly younger than the others (3-5 months). Is there a way to get rid of those bugs? And what could be causing them?
Any help is extremely appreciated

 

[ADsnail]

They could be copepods, which sometimes come in with sand or rocks. Or they could be water mites, which eat algae and may damage plants (but not fish or shrimp). Or could be a few other things, like water fleas. Could you take a picture? You'll get more positive ID here with that.