Wandering sheep sound like they're walking on wood!

Wandering sheep sound like they're walking on wood!

What I expected to happen was...:
Sheep. Oh, sheep. Gotta love 'em. After all, they're just like you, in the sense that if you're walking on dirt, or gravel, it sounds like it...
What actually happened was...:
Or does it? No, it doesn't. Sheep, for some reason, now sound as though they're always walking on a wooden block.
Steps to Reproduce:
>Be me
>Be sexy
>Need to make a bed, so approach a sheep...
>WHAT?! That's grass, not wood, buddy. Why does it make woody, creaky sounds?