What are these things

[StartingATank]

I have had these in my tank for a long time and they have never worried me, but now they have gotten pretty large so I am wondering what they are. If it helps, I would say they are about 1/4”-1/2” long

 

[tbrown]

Are you referring to the amphipod?

 

[StartingATank]

Are you referring to the amphipod?

I believe so, I always thought that that was what they were, but I was never sure. Thanks!