With a long cylindrical body that curls under its own abdomen, this fly looks rather odd, as do all 25 British species belonging to the Conopidae family of thick-headed flies, the family of beegrabbers and waspgrabbers. The rust colour of this particular species has led to its common name Ferruginous beegrabber (Sicus ferrugineus), and it really does grab bees.

Female beegrabbers linger on and around flowers, waiting for their prey – in this particular case, various species of bumblebee – not to eat the bumblebees but to grab hold of them and, using their ovipositor, inject an egg into the bumblebee’s abdomen. After hatching, the beegrabber’s larva develops inside the abdomen of the bumblebee while it’s still alive, though the bumblebee does eventually die and the larva pupates inside the corpse.

Sicus ferrugineus is common throughout most of Britain and Ireland, and the adults can be seen from May to September. Look for specimens sitting patiently on flower heads waiting for some unsuspecting bumblebee to fly in.