I checked the coop last night around 8 pm, and they were there this morning when I checked at 830am, so I'm hoping it was 3 different chickens that are all new to laying. I had someone who was hiding eggs in the corner behind the feed so I check all over now. I'd previously had 2 soft shells, one a few weeks ago, and one yesterday, but I have 3 girls who hit 19 weeks old yesterday, so I just dismissed it as them being new layers. I have given them oyster shells and have been crushing used eggs to feed them. I'll try tossing the oyster shells in w/ their feed to see if they might eat more of it. They seem to knock more of the shells and grit on the floor than ingest it.