Initially, the cattle mutilations evidenced a technology to evidently literally cut between the cell walls--probably with a laser like device.
In recent decades, the picture has evidently become more muddled with tales of government types doing such with their own UFO craft and staging them to implicate the ET's.
But, clearly ET's have been at it, probably much longer and much more extensively than we have.
And, some people do not think that even now that we have the technology to drain absolutely every drop of blood and to do the other technically challenging aspects of such.
But the animal mutilations are not the most disturbing aspect--it's the vastly underreported human mutilations of exactly the same sort--all with the humans clearly awake, alive, as long as possible, while undergoing the horrific procedures.
The nonsense that wolves and such are doing such is just ignorant. Predators and other animals will leave the carcasses a wide berth for months. And, they tend to attract no flies and to fail to deteriorate for very extended times.
Again, Linda Moulton Howe is a great expert on the subject.
The NM Congressman who drove a GAO study into the thing eventually muffled and sort of aborted the explanations he might have given. The consensus was that he'd been ordered in no uncertain terms to do so. Then, he died not that long afterwards of cancer, as I recall.
BTW, just as a thought experiment . . . how would
YOU
explain
the following evidence:
1. cow heard bellowing as she's observed rising in a cone of light into a large silent craft hovering overhead
2. There's no tracks into the new fallen snow except the cow's tracks.
3. The cow is later dropped roughly from where she was lifted though from a few to several hundred feet.
4. No predators will get anywhere near the carcass.
5. The local law enforcement admit to receiving lots of reports of such but refuse to comment further or to have anything to do with the case.