I had a slightly different experience--a raccoon or something similar got into my cache and scattered the contents all over. There had been a container of Silly Putty in there, which a friend told me an animal might try to get at(??)Maybe he was right. From now on, no Silly Putty, even tho I still think it is a great cache item otherwise.
And nothing but watertight ammo boxes from now on--like to see a raccoon get into one of THOSE.
Never have seen wildlife in the close vicinity of a cache so far, but I think that's a strong piece of evidence that caches (and cachers) are generally environmentally friendly, and not harmful to the area--most cachers are fairly respectful, not typical tourists, and don't throw cigarette butts and soda bottles wherever they go, either.