The weather is fairly mild these days and I have been spending a lot more time outside. I've been noticing that one of the ducks, (they are usually close together so its hard to tell which one) makes a "weird" sound. The best way that I can describe it is similar to a cat purring. Is this a content, happy sound or a "back off" type of thing? They are somewhat skittish so I try to spend more and more time in close proximity to try to get them used to me. They are to a point that if I am watching them from outside they are ok, but still slowly coming around when I go inside the barn.