I was reading a piece on the results of several (past) deer-repelling experiments regarding different types of "deer repellant" that were tested in some areas that I have hunted.

What I found interesting was the successful results when using various compounds that contained certain chemicals, foods, or food by-products that many of us use or eat e.g. vegetable oil; lemon extract; oleoresin of capsicum (hot peppers), eggs, citrus, garlic, onions, fatty acids, fish, vanilla, etc.

The question is: Is it the combination of certain ingredients that creates a particular odor or taste that can (possibly) repel deer, or can the odor or taste of a single ingredient be the main repellent?

All I know is that I am not going to make it a major concern. In fact, after reading about all the foods and spices that are involved I got powerful hungry and now have go fry several eggs, some chopped tomatoes browned in a batter, some sautéed onions, a pile of fresh cut potatoes, 2 or 3 jalapeno peppers, and a cup of hot and strong black coffee.

http://www.walnutcouncil.org/deer_repellent_study.htm