Narcissus bulb fly, or, Merodon equestris, is a bee-mimicking hoverfly whose larvae feed on plant bulbs, more specifically, the bulbs of plants belonging to the Narcissus genus. These flies are frequently sighted in the garden as well as in flowery suburban habitats. There are also variants within the species, where each mimics a different species of bumblebee. Mimicry in nature is an evolutionary adaptation that's used as a form of defence. In other words, these flies trick other wildlife into thinking they have a nasty sting, so predators tend to keep their distance.