The "evil" animals of ME

[Birdland]

One thing that always bothered me about Tolkien's mythology was how the characters seem to be constantly under attack by evil wildlife, mostly under the control of Sauron.

You have the wargs (wolves) of course, spying birds, attacking bats in The Hobbit, man-eating spiders, black squirrels, (evil squirrels?!), the cats of Queen Beruthiel. And I'm sure there are others that I've forgotten.

The only one he seems to have overlooked is serpents, and I'm sure they're covered someplace in the Silmarillion.

Now I'm not talking about mythological creatures, like the Nazgul's steeds, or dragons, but just your everyday fauna. They're all evil!

The only wild creatures I can think of that were on the "good" side are the Eagles. All other creatures were domesticated, like horses and dogs. Then there is the fox mentioned in The Shire, who is basically clueless as to what's going on.

These days most of use have a more benevolent view of wildlife. Wolves have an admirable social structure. Bats and spiders are beneficial. Crows and ravens are wise, etc.

Was Tolkien's view just part of the old "man vs. nature" beliefs of the time? Did he not "like" or observe wildlife? Was he just playing on ancient fears? Why does it seem that everything "natural" in Middle Earth is portrayed as the enemy?