Black bugs in tank?

[BabyShark]

Recently discovered these black critters crawling in my tank. At first I only noticed a few, but tonight I decided to check on my tank hours after lights out and noticed a lot of them crawling all over the rocks and on some coral as well. It’s hard to take a picture so I attached a video link. Could anyone please help me identify these critters and if they’re a threat to my reef.

 

[Terri Caton]

Pods. They're a very good thing.

 

[BarSnackz]

I agree

 

[huckjai]

Those are amphipods. Generally very good to have. Some amphipods are parasitic, but seems to be quite rare.

 

[Thespammailaccount]

Pods! Great in a tank!

 

[Bryce M.]

Good boys!

 

[BabyShark]

Okay I figured they were a sort of pod! still fairly new to the hobby. Thanks for all the responses!