I got some for the first time a few weeks ago. They are always in a pack in the upper corner of the tank. Even when I seperate them they find each other. Every now and then one is crawiling up a powerhead cord out of the water.
Have you ever found any completely out of the tank ?
Yes. They are coastal dwellers. They have to come out of water to breathe. And they do clump up. Might be an instinctual thing. No idea.
Didn't sleep till after 3 last night.