I figured out which chicken has been laying the pullet bullets. She has laid one a day since she started, although only the first one was in the nest. The rest have been in the farthest corner of the coop that I have to really work hard to reach. GRRR. It is Titan, our EE with the impressive beard and muffs. Shame they're blue though. I already had 2 blue layers, i was hoping for some shade of green.