I was fishing with my granddaddy on a summer afternoon. Like many boys, I was more interested in wading in the water than waiting on a bite. I abandoned my cane pole to go swim. Emerging from the water, I discovered a black leech stuck to my leg. “Don’t pull it off,” my granddaddy advised, “we’ll have to burn it off!”

Leeches suck the blood from their target; spirit leeches suck energy and passion from theirs. Some spirit leeches are dark—they remove optimism, hope and confidence. Mention an opportunity; they can tell you why it’s a mistake. Some are transparent, preying on personal accountability. They play the blame game or bring out the excuse use. Some are almost invisible, specializing in putting wet blankets on joy, new and change—all important building blocks of learning.

Spirit leeches are removed the way real leeches are—with fire. Not a match, but the heat and energy of spirit. As a mentor it is vital you choose the spirit of greatness. Be a role model of and advocate for passion. Choose the light over the fog. Don’t be a slave to ritual. Helping your protégé learn to break the norm can provide enrichment and growth. It can help them learn adaptability and tenacity. Remember: spirit leeches are fans of subtraction, not addition; and, learning is about addition. But, they stay clear of people on fire with excitement and resolve. Light up with happiness and they disappear!

If you are looking for more about this important topic don’t miss “7 Things That Kill Your Productivity at Work” posted by Jacquelyn Smith on May 18, 2013 on Forbes.com.