When I lived in Georgia, one of the horse pastures only had one water trough. I would fill it in the morning, refill it (bone dry) at lunch, and refill it before I left at the end of the day. After bugging the boss for a couple weeks, we finally got a second one and it wasn't a problem after that.
But at mid-day when I refilled it for lunch, the horses would gallop over and start dunking themselves in the trough. They'd splash it all around, try and steal the hose from me when I was trying to fill the trough, and a couple of them would literally dive into it. Not their whole bodies, but they made sure that their front legs were in there. Trying to satisfy 8 hot, miserable horses by hosing them down one by one and trying to fill the water trough took a while. They'd chase eachother out of the way when I was hosing down a particular horse...it was a circus.
Again, we got the second water trough finally and it was HUGE, so we never had a problem after that. But for a while it was crazy!