The researchers found that the bees' guts are rich in acid-loving bacteria similar to those found in vultures, hyenas and other animals that feed on carrion.

Their study was released on Tuesday in the journal mBio, published by the American Society for Microbiology

Only three species of bee in the world -- all vulture bees -- have evolved to get their protein exclusively from dead meat, and they live only in tropical rainforests.

However, there are other bee species that will consume fresh animal carcasses when available but also forage for pollen and nectar, according to the study.

Bees and gut bacteria

The guts of honeybees, bumblebees and stingless bees are colonized by the same five core microbes, and they have retained these bacteria for roughly 80 million years, the study noted.