"Zombie bees" have now invaded eastern U.S., according to media sources.

Anthony Cantrell- a beekeeper in Burlington, Vermont discovered "zombie bees" in his hive in October, according to the Associated Press. This is the first report of 'parasitized' honey bees being found in eastern U.S.

The zombie bees aren't half-dead bees and they certainly don't roam the earth forever. These bees suffer from a parasitic infection that disrupts their neurological functions, leading to strange, "zombie-like" movements. The honey bees die within a few days. "Right now, we don't know if it's an isolated thing," Stephen Parise, Vermont agricultural production specialist, said Tuesday at the state's annual farm show, Associated Press reported.

San Francisco State University researchers led by Professor of Biology John Hafernik were the first ones to discover this strange bee infection in 2008.

What are Zombie Bees

A fly called Apocephalus borealis, lays its eggs in the bees' abdomen. The eggs take about a week to hatch during which they disrupt the neurological function of their hosts. The larvae then enter the world from their hosts' body through the head.

"When we observed the bees for some time-the ones that were alive-we found that they walked around in circles, often with no sense of direction," Andrew Core, an SF State graduate student from Hafernik's lab said in an earlier press release.

The fly was known to parasitize bumblebees. Until last October, the parasite was only seen in bee hives in California and South Dakota.

SF University researchers had warned in 2012 that the honey bee population is quite susceptible to the newly emerging parasitic fly- A borealis.

"[Furthermore] the domestic honey bee is potentially A. borealis' ticket to global invasion. Establishment of A. borealis on other continents, where its lineage does not occur, where host bees are particularly naïve, and where further host shifts could take place, could have negative implications for worldwide agriculture and for biodiversity of non-North American wasps and bees," John Hafernik and colleagues had written in a study article published in 2012 in PLOS One.

Honey bee population in the U.S have become homogenized as farmers usually shift them to different parts of the country. The fly could have hitched a ride with honey bees sent to Vermont.

"It's not surprising; it's certainly not good news," University of Illinois entomologist May Berenbaum told Associated Press. "There are so many pathogens and parasites that we're aware of that are afflicting bees."