My fish are just plain DUMB!

[MMAX]

I had the same problems with my orange spot goby and more recently my lawnmower blenny (always thought he was too fat to fit through the egg crate but he suprised me). I shut down my return pump and opened the gate valve to drain most of the water out of my overflow. Raised my lights, stood on a chair and leaning over the tank used 2 nets to trap the little bastards. I kept one net stationary and used the other to chase them in. I got pretty good at it because they didn't learn their lessons after the first time.