Are these fiddler crabs and why are they in my pool?

I went out this morning to skim the pool and check the chlorine levels. I am used to finding frogs, sometimes lizards and an occasional snake and sometimes a lone crab or crawdad. This morning my pool was full of these little buggers! One male and a bunch of females. I think they are fiddler crabs and I think they were having a party in my pool! It took an hour to scoop them all out, one at a time and they are fast! They didn't want to be caught.
The resaca(water, like a slow moving river) is about 200 ft from the pool, did they crawl all that way just to go for a midnight swim?
The lone male

One of the females.

Wow! that must have been something, What strange looking creatures they are!
What did you do with them?

I took them to the fence and put them on the other side so they could go back to the resaca and so the dog wouldn't eat them.

That cures me from ever coming for a swim at your house Susie.

Imagine those nipping on your toes Kell!(sure beats a gator in the pool though)

Yeeks! What in the world are they? and why are you treating them like an endangered species? Do they bite and are they poison? I never seen or heard of anything like that down this way?
lol.
Sylvia

They're just cute little fiddler crabs.... wouldn't hurt a thing.

I know there are hundreds of them down by the water, but they're too cute to let them drown in the pool. The male didn't even pinch me when I picked him up and put him over the fence.

Cool ! How big are they?

They are small, about 2 inches across their little bodies. Their pinchers don't hurt at all, they are so small. Down by the resaca, there are fiddlers from 1/2 inch bodies to this size. I don't think they get much bigger.