Snaring small game is a skill mostly of observation. The loop diameter, distance from ground and placement must all be correct. Then for every dozen OR MORE snares correctly placed you MIGHT catch one animal. Pre made snares do have a locking mechanism. It really isn't neccessary. A simple bend or kink in the wire will suffice. Many manuals better illustrate this than I can explain. You can also double up wire and carefully twist it into one strand for greater strength and reduced slickness. I never did catch anything during Arctic Survival School. But then our area was so heavily used by former classes the smarter rabbits had moved out and nobody else did either. But I was a smart rabbit, taking a lesson from my furry friends. I secretly cached a dozen Hershey Bars inside my parka. I still do in one form or another. I'd have nightmares about killing bunnies. Chocolate? I have no mercy or moral hesitation.