While my friend was away on vacation, I got the opportunity to look after his hermit crabs. I had also recently purchased an intervalometer for my DSLR camera, so I could do time-lapse photography. The video below shows a rough test of that, with each frame 8 seconds apart. There are quite a few things that need to be fixed for my next attempt. I have to fix the depth of field so more of the tank is in focus, the ambient lighting could be a bit better, I have to cut down the reflections on the front of the tank (perhaps a light source from behind), fix the white balance, and not move around when the photos are being taken. That final point is what makes some frames darker than the rest.
Anyway, more about the hermit crabs. I have two tanks, three crabs in each. The crab you see moving about here has ADD, I think. It just doesn't stop moving. Every now and then I see the other crabs moving about, but I haven't seen any of them use the 'hamster' wheel like this one does.