I think that maybe it's dislocated or sprained. Sounds like she may well have a nest nearby. I'd leave her alone in that case, as she still seems able to get around, and if there is a nest, taking her away would be lethal for the little ones. Also, her mate will miss her. Sometimes it's best to leave well enough alone. However, I love animals/wildlife as well, and would probably keep an eye on things to see if any ducklings appear, and to at least monitor her progress, if any. Sometimes we must trust in nature!

I tried to save an injured bird once (not a hummer) and it had the same shivering reaction. It died shortly thereafter. I think it was frightened to death. Please call a local animal shelter. They should be able to refer you to a wildlife rescue group. I don't know if they will advise you to just release it or come and pick it up, but they will know what to do. In some places, it is illegal to keep any wildlife even for rehabilitative purposes...

Is this, by any chance, a youngster asking this question?

I would suggest finding your local wildlife rehabilitator; here's a link from the humane society to illinois rehabilitators: http://web.extension.illinois.edu/wildlife/files/WildlifeRehabbersSheet.pdf When moving bats, use thick gloves or a towel to pick it up only if necessary (we had some confused babies get into our house, and that's how the wildlife guy removed them for us). If it isn't actually injured, make sure to put it back outside somewhere high up (like on top of a bush); bats have trouble taking off from the ground, since they more glide than fly -- if they are on the ground, they have to run a long way in order to take off. As for what bats eat ... I think the little brown bats around here eat mosquitos, but they might eat other things, too. It might eat fruit or bugs. I would also keep it away from any other animals and clean any areas that it is near thoroughly as they can also carry things like ringworm (which is actually a fungus, not a worm), and yes, humans can get ringworm, too. Little brown bats have recently had issues with white nose syndrome, which I don't recall whether it's a fungus or something else, but it exhibits as white stuff on the nose of the bat, as the name implies. It does bat things to colonies, and I think it's fatal, so if the bat has white on its nose, that would be very bad and probably best to give it over the the center.