Ocellus

An ocellus is the simple eye of adult insects (and some larvae) that allows them to capture variations in brightness. A certain number of insect species have one to three ocelli - most often three, placed in a triangle on the head - including Diptera, Hymenoptera, Odonata, Raphidioptera... An ocellus may also be a patch in the shape of an eye on the wings of insects, bird feathers, mammal fur...