
Like those shots - your shrimp look happy. Don't be surprised if you don't see them for days and then see them all the time. They are a bit contrary.
I just had a weird experience with a wandering shrimp. It was an amano in an open top tank. I hadn't even realised it had got out of the tank until I found it's corpse a good 30 meters - out of the tank, out of the room, onto the landing, down the stairs and into the hall. Poor thing. I've moved the remaining shrimp from that tank into one with a lid - they like to wander.