I generally do not kill snakes, even the poisonous snakes. My dogs kill enough of those and snapping turtles without my help. Losses to snakes pretty light. That snake clearly looking for mice. I put an egg in front of and it simply crawled past even though in hunting mode.
I just read the PDF. They did a pretty good job on that. I don't like deer stops because I have lost a few fox and coyotes I've had by the leg. However I've been snaring/trapping for the past 15 yrs and I've only had to release one deer. They have stepped into hundreds though. Never got one by the leg. That deer stop does work. If you do it buy them already premade and loaded to close quickly. I can make them but there's a learning curve to get them to close quickly and smoothly.
Technically I'll typically close em on Christmas Eve morning and reset em on dec 26th morning. To improve my image I do let all young raccoons and beavers go. Also anything with screwed up fur I'll turn loose as long as it's healthy.
Skin them, flesh the hide, hang the pelt on a stretcher or tack beavers to a board to dry. Sell the fur. Doesn't everybody?
