I have noticed that bed bugs don’t easily fall into pitfall traps. The primary behaviour is to hang on to the top edge of the trap and go round and round. As a lark I decided to see what would happen if I made a pitfall trap out of a box cutter blade – very sharp. I covered most of the lower portion of the blade with masking tape allowing the bugs to climb to the top. The bugs did climb to the top and appeared to walk very easily on the knife edge. I had expected the blade to cut the feet off the bug but no such luck. They appeared uninjured.