The trap used was a leg-hold trap, what most people think of as a "bear trap"--a spring-loaded metal trap with two jaws. When the animal steps in the middle of the trap, the jaws spring up and clamp the animal in place. There is a debate about whether these traps are humane or not; the actual traps usually do not harm the animal (some newer traps are padded or laminated to avoid even breaking the skin) but in some animal species, the animal will attempt to chew its own leg off to escape from the trap. Some states have banned all or some of this type of trap. Steel-jawed traps, which can break bones or introduce infections, are banned outright in New Jersey and California, for example. Leg-hold traps are sometimes used for catch and release, as well. "Yep, there have been cases where wolves have been trapped with leg-hold traps and then released," says Provost. "It is probably one of the best traps to use for catch and release." Animal welfare organizations like Born Free disagree, citing studies that claim the steel-jawed leg-hold traps are inhumane. "Leghold traps can cause severe swelling, lacerations, joint dislocations, fractures, damage to teeth and gums, self-mutilation, limb amputation, and even death," writes Born Free on its site.