You couldn't make this stuff up - http://news.bbc.co.uk/earth/hi/earth_news/newsid_8261000/8261364.stm
Then again, perhaps it is made up -
Rodents are not known to eat meat or hunt animals, so it is unclear why the squirrel would launch such an attack.
Really? So insects aren't animals any more? When did that happen? Perhaps the reason rodents don't hunt "proper" animals is that mostly rodents are the smallest mammals (proper animals?) about.
Hell - what do I know? I just read stuff and observe things around me. I'm not a "proper" scientist.
Thankfully the web has a plentiful supply of "dead squirrel" pictures to maintain balance.