One of the blogs I follow is thisisphotobomb.com (warning though, sometimes the content is questionable). Basically a photobomb is when someone gets into a photo either deliberatly or randomly in the background who isn’t supposed to be there, say someone making bunny ears behind your head or jumping into the shot just as the photo was taken.
This is slightly different…
You can read the story here, but basically the squirrel seemed to be interested in the noise made by the self timer on the camera.
Of course this has since led to the squirrel appearing all over the web, the best one I’ve seen so far is: