Olfersia cervina, commonly known as the deer fly, is a type of biting fly that is found in various parts of the world. There are several other terms used to refer to this species, including the common deerfly, yellow fly, or mangrove fly. In some regions, it is also known as boucon, cabimbo, or taon cerf. This species is known to be a pest to humans and animals alike, and is notorious for its painful bites. Some common ways to repel deer flies include wearing long-sleeved clothing and using insect repellent. Despite their nuisance, deer flies play a role in the ecosystem by serving as food for some species of birds and fish.