Theo and Russ:

You're pretty close...the shells of "hatched" eggs basically show a round cap sorta pecked off the fat end, with the rest of the shell more or less intact. Lil 'uns use that egg tooth to do this...

If the nest has been raided, the shells would be pretty much hacked to pieces...no pattern at all.

BTW...cleaned out the box on the pond and it had an old nest in it...success. Did the one on the creek and it had a huge squirrel nest jammed inside...oh well. However, I was a bit leery of dumping that out. Figured I'd catch a pile of pissed off tree rat, but it was unoccupied at the time. Used chain saw to clear limbs about 5 feet away from that one. Hopefully, Mr. squirrel sees it's just too much work to get back in that one...we'll see.

In a lifetime, the average driver will honk 15,250 times. My wife figures I'm due to die any day now...