Scientists have discovered a new species of phorid fly in Thailand that is believed to be the world's smallest fly, according to a paper published in the latest issue of the Annals of the Entomological Society of America.

The tiny fly, Euryplatea nanaknihali, was discovered by an Inventory Group for Entomological Research in Kaeng Krachan National Park, Thailand. It belongs to the fly family of Phoridae, which is known for "decapitating" ants.

The species is the first of its kind to be found in Asia. The phorid flies have hump-backed appearance.

The smallest fly is just 0.40 millimeters in length, 15 times smaller than a house fly. The fly can possibly behead ants of the Crematogaster (Formicidae) genus that are as small as 0.5 millimeters.

"It had always been assumed that smaller species of ants would be free from attack because it would be physically impossible for flies that are 1-3 millimeters in length to develop in their relatively tiny heads," said author Dr. Brian Brown of the Natural History Museum of Los Angeles County.

"However, here we show that even the smallest host ants in a host-parasitoid system cannot escape parasitism," he added.

The specimen, a female, is said to have smoky gray wings and an egg-depositing organ that makes it easy to lay eggs on another insect.

Though the fly decapitating the ants have not been observed, it is evident as the species' closest relative known as the Euryplatea eidmanni can infest on tiny ants in Equatorial Guinea.

According to Live Science, the fly is capable of decapitating on small ants and laying eggs on their body, which eventually migrates to the head part. The eggs feed on the muscles used to open and close ants' mouth parts. They gulp down the ants' brain and cuts off their head.

The fly then resides in the ants' head for another two weeks until it grows fully into an adult.