While planting insect-repelling aromatic herbs such as lavender, rosemary, basil and mint around your coop will make it look attractive, the herbs won’t ensure that your coop is insect-free. The essential oils in these herbs act as nature’s bug repellent; flies and mosquitoes tend to avoid them. However, the concentration of oils isn’t sufficient to offer a complete insect-free zone — you may find that there are fewer insects, but not a total eradication.