I feel so guilty cos I've lost Galvatron the hamster!Help!?

It was my own stupid fault he seemed ok running about then he disappeared. I've done all the usual stuff, checked everywhere with a torch, set up a pitfall trap with a bucket and a ramp, and put out food for him. I know that he around, as he has definitely eaten some food I left out. His cage is on the floor and open so he could easily get back in it. Has anyone got any other tips?The next step is setting up a Longworth trap to catch him, but I'm really wary about it, as from personal experience they cause stress.