Hover flies are true flies, not bees. Flies have one pair of wings, and bees have two. If you can get them to hold still for a moment, you can easily see the difference. Hover flies are excellent pollinators and have the ability to remain seemingly motionless in mid-air. Many insects, including the one below, have developed markings that make them look like bees–mimicry that protects them from some predators.