Before I get to that, let me explain the traps. As a farm goes, we have animals. Animals require feed storage. Both animals and feed attract predators. They also attract opportunists, and sometimes just passersby. Knowledge of how to deal with each of these scenarios has been trial and error.
First, the error. When you have live animals that feed off of the ground, chemicals and poison are a big NO. (Probably a big NO in general, but we can debate that another day). We cannot fertilize our grass, nor can we use any kind of pesticide or poison that would normally do a nice job of keeping rodents at bay. In one non-chemical experiment, we tried using glue traps outside, and horribly, managed to catch some small birds that were irreversibly entangled in the muck. Never again. Another small scale method of rodent abatement, the mouse trap, has been used with some success but relies heavily on the trap setter to keep them baited and set. False trips are common and render the trap temporarily useless.
Our trials include, using sound and vibration to deter moles (doesn't work), assuming that animals kept in enclosures surrounded by wire are safe (not always), assuming that an enclosure that worked well for 3 years is predator proof (not always), keeping feed in containers eliminates loss from uninvited diners (not always).
On that last item, be clear, wildlife does not also mean dumblife. These guys know how to tunnel under, climb, lift, jump, reach through, rip open and unclasp just about anything you can think of, to get a meal. If that means figuring how to open the lid on a feed bin, they will do it. Sometimes that meal is a chicken. In fact, pretty much everything loves a chicken. Protecting them is a full time job.
So we started trapping using live traps. It was the best way to eliminate the option that we might harm a pet, or other unintended capture. It works. Sort of.
When we are diligent with the traps, we are successful.
So we trap and remove anything that is deemed a threat. It keeps our chickens happy and healthy, and we all sleep a little better at night.