I just need to point out one thing here...

These river rats wouldn't sit still at all. They must have had ADHD or something.

Those are not "River rats" those are called beavers. They live in the remote jungles of the amazon and eat bald eagle babies. They are nocturnal so you are going to have a hard time catching them with a lens that is not a nocturnal lens. (not ADHD) just running around to find a dark place.