Crabs etc and Soda Water

[gregzz4]

Did the trick. I used 1 2-litre bottle in a 2 gallon bucket, and then a second bottle to pour over the rocks. I found 3 crabs.
It also flushed out a bunch of amphipod shells. None of them were swimming when they came out, so I'll say they are just shed exoskeletons.
I also found one of those 'wood bug lookin' things swimming around.
Anyway, it looks like all the crabs are the same breed, once I look at them in the pics, even though the smallest one first looked like a Pom-Pom.
I think they are Porcelains but I don't know enough yet to call that for sure.
I'll take them in to JL in the next day or so, but what do you all think about what kind they are?
Friendly or not?