Bad Astronomy

Rats!

So I’m sitting outside on my patio on New Years Day (it’s sunny! and warm! and I have an old friend visiting, so it’s very pleasant!) when I look down on the concrete and see this little guy:

I think it’s a rat bone, perhaps a tibia, but the web is coming up empty on close up images. It’s too big to be a mouse, I think, but still pretty tiny (it’s not a smilodon bone, for example). Here it is with a ruler:

It’s about 2.4 centimeters long, and gently curved. One end is clearly a hinge joint, and the other splays out a bit, but still looks like a hinge joint.

OK, bioBABloggees. Any ideas? We’ve seen rats in our area before (they’re cute!), but no rabbits, and only rarely any squirrels. Could it be from a bird? An alien? An angel? Whaddya think?