In the old coop they sat on blocks but I like them hanging better. They used to try and jump on them but they are were to unbalanced and would hop back off.
Okay, finally got pictures!
They hang about one foot or so off the ground. Mice can't climb up or down to get into the feed. Mine are sorta in the coop so they are protected from the rain but I'm pretty sure the buckets are water proof.
With the feeders, it needs to be somewhere where the weather won't get to it. If it's out in the open and it rains, you have wasted feed. I use 5 gallon buckets with these things attached.
I keep them in the covered part of my run.