Mimicry is a phenomenon in nature typified by one organism sharing similar perceived attributes with another, such as a drone fly resembling a stinging honey bee. Mimicry serves many functions besides defense, for example cuckoo eggs mimic those of their host. It also need not be visual, as in spiders that attract moth prey by biochemical mimicry of their sex pheromones. The mimic and/or model does not have to be an animal either, for example plants and even fungi can be mimics or models (but generally not dupes - the organisms 'fooled'). Mimicry has been important in the history of evolutionary thought, providing early evidence for Charles Darwin's theory of evolution.