Mark is a practicing entomologist with many decades experience observing and collecting insects in many ecosystems across the globe. He has named a number of species of ants and has a butterfly named after him. Mark has published roughly 60 peer reviewed papers and chapters in books on various groups of insects. Much of his research has been focused on ants. He has taught classes at Art and Science in the Woods over many years and strives to customize his classes so students gain insights about the natural world and expand their interests.