I think mine were waiting until lights out as well it's like the little devils knew not to do it when I could catch them.My torch never recovered from that, the problem is that I don't know how those crabs knew that they only did it after dawn, I already saw the torch a little closed but one day I had to get up at 3 am to work and There was 1 eating the torch and I immediately took it out and watched the other one for days but nothing, until one day I set the alarm for 4 am and it was eating it too