Andy Sands / Robberfly (Machimus cingulatus) head close up showing large compound eyes. Captive, UK, July.

Wild Wonders of Europe / Ziegler / Robber flies (Asilidae) mating, one with insect prey, The Peloponnese, Greece, May 2009

Wild Wonders of Europe / Smit / Robber fly (Asilidae) with mosquito prey hanging from leaf, Gornje Podunavlje Special Nature Reserve, Serbia, June 2009

Bernard Castelein / Robber fly (Eutolmus rufibarbis) De Inslag, Brasschaat, Belgium July

Paul Harcourt Davies / Red-legged robberfly (Engelepogon brunnipes) with Damselfly (Zygoptera) prey, Sardinia, Italy, September

Paul Harcourt Davies / Red-legged robberfly (Engelepogon brunnipes) with Damselfly (Zygoptera) prey, Sardinia, Italy, September

Nick Upton / Robber Fly (Saropogon sp.) on seedhead. Karlovasi, Samos, Greece, July.

Nick Upton / Robber Fly (Saropogon sp.) on seedhead. Karlovasi, Samos, Greece, July.

Nick Upton / Slender-footed robberfly (Leptarthrus brevirostris) standing on Yellow rattle flower (Rhinanthus minor), chalk grassland meadow, Wiltshire, UK, June.

Nick Upton / Violet black-legged robber fly (Dioctria atricapilla) with a hoverfly as prey, chalk grassland meadow, Wiltshire, UK, June.

Nick Upton / Violet black-legged robber fly (Dioctria atricapilla) with Dashed slender robber fly (Leptogaster guttiventris) prey, chalk grassland meadow, Wiltshire, UK, June.

Wild Wonders of Europe / Muñoz / Robberfly (Asilidae) with damselfly prey, Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanc, Castilla y Leon, Spain

Wild Wonders of Europe / Muñoz / Robberfly (Asilidae) feeding on damselfly Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanc, Castilla y Leon, Spain

Alex Hyde / Robber Fly (Asilidae) overhead view photographed on a white background. Aosta Valley, Monte Rosa Massif, Pennine Alps, Italy. July.

Will Watson / Robberfly (Asiidae) with a captured skipper butterfly (Hesperidae), Manabi Province, Ecuador.

Kim Taylor / Hornet robber fly (Asilus crabroniformis) with fly prey (Larvaevora sp), Dorset, England, September

Claudio Contreras / Robber Fly (Diogmites sp.) hanging from leaf, feeding on fly prey. Maria Madre Island, Islas Marias Biosphere Reserve, Sea of Cortez (Gulf of California), Mexico, August.

Andy Sands / Hornet Robberfly (Asilus crabroniformis) on ling heather (Calluna vulgaris) West Sussex, England, UK, August.

Nick Upton / Robber fly (Saropogon sp) on twig, hunting for prey in amongst coastal vegetation, Samos, Greece, August.

Nick Upton / Robber fly (Saropogon sp) hunting for aerial prey on pebble beach, Samos, Greece, August.

Nick Upton / Robber fly (Saropogon sp) on twig, hunting for prey in amongst coastal vegetation, Samos, Greece, August.

Nick Upton / Kite tailed robberfly (Machimus atricapillus) resting on limestone boulder, Wiltshire, UK, August.

John Abbott / Bee Like Robberfly (Laphria saffrana) feeding on a Burrowing Bug (Cydnidae), Big Creek Scenic Area, Sam Houston National Forest, Texas, USA

John Abbott / Robber fly (Efferia prob. snowi) female in flight, Wild Basin Preserve, Texas, USA, April

Nick Upton / A rare species of Robber fly (Pycnopogon mixtus) on coastal flower watching for aerial prey from a flower bud in coastal sand dunes, Lesbos (Lesvos), Greece, May.

John Abbott / Robber fly (Ommatius sp.) feeding on Acanaloniid planthopper, Neches River, Texas, USA, June

Konrad Wothe / Robber-fly (Asilidae) in rainforest, Mission Beach, near Innisfail, Queensland, Australia, October

Bernard Castelein / Robberfly (Asilidae) on discolouring dock leaf (Rumex acetosa), Brasschaat, Belgium, June

B&S Draker / Robber Fly (Asilidae) adult with butterfly prey. Starr County, Rio Grande Valley, Texas, USA.

Nick Upton / Common Red-legged Robber Fly (Dioctria rufipes) sun basking on a leaf. Wiltshire garden, UK, May.

David Welling / Robber Fly (Microstylum morosum) perching on a dead flower stalk. Travis County, Texas, USA, June.

Nick Upton / Large Robber Fly (Machimus modestus) female with small solitary bee prey. Zadar province, Croatia, July.

Nick Upton / Large Robber Fly (Machimus modestus) male resting on rock. Zadar province, Croatia, July.

Nick Upton / Large Robber Fly (Machimus modestus) female with small solitary bee prey. Zadar province, Croatia, July.

Bernard Castelein / Robber fly (Asilidae) portrait on grass stem, Brasschaat, Belgium, July

Bernard Castelein / Robber fly (Asilidae) portrait on grass stem, Brasschaat, Belgium, July

Stephen Dalton / Small yellow legged robber fly (Dioctria linearis) with prey, UK

Stephen Dalton / Robber fly (Asilidae) UK

Paul Harcourt Davies / Hornet robber fly (Asilus crabroniformis) on dung, Italy

Stephen Dalton / Robber fly (Asilidae) in flight. UK

Andy Sands / Robber fly (Neoitamus cyanurus) resting on dead wood, Hertfordshire, England, UK

Andy Sands / Hornet Robber fly (Asilus crabroniformis) mating pair, Oxfordshire, England, UK

Andy Sands / Hornet Robber fly (Asilus crabroniformis) cleaning wings with back legs, Oxfordshire, England, UK

Andy Sands / Hornet Robber fly (Asilus crabroniformis) poised ready to take flight, Oxfordshire, England, UK

John Cancalosi / Robber fly (Asilidae, probably Efferia spp) Arizona, USA

John Cancalosi / Robber fly (Asilidae, probably Efferia spp) Arizona, USA

John Cancalosi / Robber fly (Asilidae, probably Efferia spp) Arizona, USA

John Cancalosi / Robber fly (Asilidae, probably Efferia spp) mating pair, Arizona, USA

Hanne & Jens Eriksen / Robber fly {Asilidae} pair mating, Oman

Hanne & Jens Eriksen / Robber fly {Asilidae} pair mating, Oman

Andy Sands / Robber Fly (Neoitamus cyanurus) feeding on small fly, Epping Forest, Essex, England, UK

Phil Savoie / Sacken's bee hunter {Laphria sackeni} mimics a bee and preys on them, USA

Philippe Clement / Robber fly (Pogonioefferia nemoralis) portrait on rock. Arizona, USA

Rolf Nussbaumer / Robber Fly {Asilidae} adult with prey, Rio Grande Valley, Texas, USA, June 2006

Bernard Castelein / Robberfly (Neoitamus cyanaurus) Belgium

Jose B. Ruiz / Robber flies {Asilus capraeniformis} mating pair, Spain

Hans Christoph Kappel / Robber fly (Asilidae) with Damselfly prey. France

Nature Production / Chinese King Robber Fly {Cophinopoda chinensis / oldroydi} Shiga, Japan

Andy Sands / Hornet Robberfly (Asilus crabroniformis) portrait. Close up of head, Buckinghamshire, UK

Andy Sands / Hornet Robberfly (Asilus crabroniformis) cleaning head, Buckinghamshire, UK.

Andy Sands / Hornet Robberfly (Asilus crabroniformis) poised for attack, Buckinghamshire, UK

Andy Sands / Hornet Robberfly (Asilus crabroniformis), cleaning wings with back legs, Buckinghamshire, UK.

Kim Taylor / Robber Fly {Machimus atricapillus} mating pair on brick wall, Surrey, England.

Kim Taylor / Robber fly {Machimus atricapillus} feeding on moth prey, UK.

Kim Taylor / Robber fly {Machimus atricapillus} female, UK.

Kim Taylor / Robberflies mating {Asilus crabroniformis} UK.

Kim Taylor / Robber Fly (Asilus crabroniformis) Surrey, UK.

Kim Taylor / Giant robber fly (unidentified) Trinidad, captive

Kim Taylor / Robber Fly (Machimus atricapillus) on flowering grass. UK.

Kim Taylor / Cutout of Robber fly {Asilidae} Gambia.

Jose B. Ruiz / Robber fly portrait {Asilus capraeniformis} Alicante, Spain

Jose B. Ruiz / Robber flies mating {Asilus capraeniformis} Alicante, Spain

Dietmar Nill / Robber fly {Asilidae} on flower, Bulgaria

Dietmar Nill / Robber flies {Asilidae} mating and feeding on cockchafer beetle Bulgaria

Bernard Castelein / Robber fly {Asilidae} Belgium

Solvin Zankl / Robber fly {Asilidae} feeding on fly. Sulawesi, Indonesia

Premaphotos / Hornet robber fly (Asilus crabroniformis) mating pair, the female is feeding on a Dung beetle while they are perched on horse dung, the food of the Robber fly larva, UK

Premaphotos / Hornet robber fly (Asilus crabroniformis) male rubbing its front legs together while perched on horse dung, UK

Premaphotos / Fan-bristled robber fly (Dysmachus trigonus) feeding on another member of its own species, UK

Premaphotos / Common red-legged robber fly (Dioctria rufipes) mating pair, UK

Premaphotos / Robber fly (Cyrtopogon ruficornis) male (right) bobbing his abdomen in a courtship dance in front of the female, France

Premaphotos / Robber fly (Cyrtopogon ruficornis) male feeding on a fly, France

Premaphotos / Small brown robber fly (Epitriptus cingulatus) feeding on a small fly, on heathland, UK

Premaphotos / Common awl robber fly (Neoitamus cyanurus) feeding on a small fly, UK

Premaphotos / Common red-legged robber fly (Dioctria rufipes) feeding on a fly, UK

Premaphotos / Bumble bee robber fly (Laphria flava) grooming its face with its front legs, France

Premaphotos / Kite-tailed robber fly (Machimus atricapillus) mating pair, UK

Premaphotos / Small yellow-legged robber fly (Dioctria linearis) feeding on a {Hilara sp} empidid fly, UK

Bernard Castelein / Robber fly {Neoitamus cyanaurus} covered in dew, Belgium