Didn't some guy use his mouth to hold film and do pinholes from inside his mouth?
There was one fellow back in the 1980's who actually used a hole between his teeth or holding his lips open just right was able to make photographs with NOTHING but film. Here's another guy; pretty impressive stuff, in my mind:
www.pinholephotography.org
But, thankfully, I don't think anyone has used a non-human animal to do pinhole.
Yes, I certainly agree with that; the point being though, just about everything has been made into pinhole cameras. For a while, it got downright tiresome. As if the point was to make something into a camera that hadn't been used before. There was a lot of stuff and lots of it was ingenious, but I soon got pretty tired of it. Check out early Pinhole Journals; full of it.
Did you hear about the cat in Seattle, Cooper, whose pet humans attached a digital camera on his collar, on a timer? He's done some great stuff. There's a flickr site which alludes me at the moment, but here's his blog:
http://cooper-catphotographer.blogspot.com/
And you, too, can put your cat in the running for a Purrlitzer Prize. Cameras are available from:
http://www.mr-lee-catcam.de/pe_cc_o1_en.htm
It would be a hoot and a half to mod one of these cameras to make it into a pinhole.
I've been thinking of getting one for Scooter.