Fox are actually pretty easy, if you can figure out their routine. They tend to visit their mouse hot spots routinely and often in the same order.

Fish always works best for me. I always have some that are outdated in the freezer.

Nuoc Mam is my go to scent. Most predators find the stuff interesting. The good stuff really stinks and lasts for weeks. I've even watched Deer come in to check the smell out. The cheaper the better, the stuff produced in Vietnam and imported is definitely the best.