According to The Hamburger Report by Clear Labs, burgers contain DNA, from rats and even humans.

The lab tested 79 brands of burgers from 22 retailers in California, and made some gruesome discoveries. The company found DNA of a rat in a fast-food burger, and a vegetarian burger contained beef.

The company also found human DNA in a frozen vegetarian burger, probably from hair, skin or nail that was mixed during the manufacturing process.

The lab said that while the findings are disturbing, the presence of human DNA or rat DNA is not likely to be harmful to humans.