I got to WATCH Summers switch shells last night! It was amazing! Mom took Ryan out for a special "grandma and grandkid" dinner so it was just me and the crabs (uh, that didn't come out quite right) at home. I went into Ryan's room just to check on them and there was Summers in his green painted shell sitting on the water dish. The other two were still hiding out.
I left and turned off the light.
Went back about 30 minutes later, turned on the light, and there he was, halfway out of the green shell and holding on to the front of the striped shell. I quickly turned the light back off and sat on a chair in front of the crabitat. It was REALLY dark, so I could just barely see, but he crawled out of his old shell and into the new one. I waited about 10 minutes and turned the light back on and there he was, in the striped shell.
He was still in it this morning so I'm thinking maybe he's finally made up his mind? I never knew they'd go back and forth and back and forth like that.
Oh, and to ladybug15057 who asked about the selection of shells in the crabitat - there's a HUGE variety in there including the turbo snail shell that you recommended. None of the empty shells are painted (well, except the one that Summers just vacated). I can't do anything about the fact that two of the crabs arrived in painted shells - that's how they came from the store and I wasn't the one who did the purchasing. Thanks for the resource information. I will be sure to check it out. As for our interaction with the crabs - I'm going by activity level. Summers has stayed out and about the whole time so we've interacted with him a bit. The other two, except for the first day, have holed up so we've left them strictly alone. I figure they'll let us know when, and if, they want to be social. Thanks again for your interest.
More crabby updates to follow.