No toxicants are currently registered to control porcupines. Some speculate that the high tannin content of the porcupine's diet neutralizes the strychnine, giving them built-in resistance to high levels of this toxicant. Animal repellents do not seem to deter porcupines. Porcupines can be controlled by trapping if dens or trails can be identified, or animals can be lured to traps. Live traps allow the release of non-target animals, but have the disadvantage of having to dispose of the porcupine.
Porcupines are difficult to lure to traps.
Common baits include sardines and a variety of smelly home brews rather akin to catfish bait. Idaho state regulations require you to purchase a trapping license and mark your traps with your name and address. Hunting is the most species-specific and efficient method to control porcupines. During this time, porcupines appear to use roads as the fastest methods of finding mates. Be sure to check with your local Fish and Game officer to see if this is permitted and make special arrangements if necessary.