Why do small animals tend to get angry a lot?

While taking a small break (heh) from my work. I went and made this little creature up.
It's not really meant to be any particular animal. It does have this look that reminds me of it being a cross of a chihuahua and a fox.

But I guess I could do a couple more pics of it. Maybe, make it less angry.


Also.. I think I have an idea for this pose... ;)


Note:
What it's sitting on is just a rock.