Stephen Dalton / Horse fly (Tabanus sp) male taking off from poppy seed-head (Papaver rhoeas) Sussex, UK

Pal Hermansen / Hoverfly in flight, backlight, Norway, September.

Jan Hamrsky / Summer mayfly nymph (Siphlonurus lacustris), Europe, May. Controlled conditions.

Jan Hamrsky / Summer mayfly nymphs (Siphlonurus lacustris), Europe, May. Controlled conditions.

Jan Hamrsky / Case-building caddisfly larva (Trichoptera), Europe, June. Controlled conditions.

Jan Hamrsky / Hacklegill mayfy nymph (Potamanthus luteus), Europe, July. Controlled conditions.

Jussi Murtosaari / Garden warbler (Sylvia borin), catching flies in willow tree, Korpoo, Uto, Finland, May.

Jeff Vanuga / Ephydrid flies (Ephydra sp) that eat microscopic algae and survives during the winter in thermal pools. Biscut Basin, Yellowstone National Park, Wyoming, USA, January.

Ann & Steve Toon / Cape buffalo (Syncerus caffer) crossing the Chobe River, followed by swarm of flies, Chobe Game Reserve, Botswana, Africa.

David Tipling / 2020VISION / Alder flies (Sialis lutaria) hatching on River Wensum, Norfolk, England, UK, June

Mary McDonald / African lion (Panthera leo), resting on a rock, surrounded by flies, Masai Mara Game Reserve, Kenya. November.

Markus Varesvuo / Osprey (Pandion haliaetus), adult in flight carrying fish. Kangasala, Finland.