Riddle: What is the smallest thing in the world?

Scientists from the University of Queensland in Australia discovered the world's smallest mysterious creature deep under the sea in the west of the country. The creatures, which are smaller than bacteria, were discovered offshore in sandstone dug out from a depth of about 4.8 kilometers under the sea by an oil drilling platform. It is called a billionth of a meter because their bodies are so small that they are measured in billionths of a meter. Their body length is only 20 to 150 billionths of a meter, smaller than a cell, even smaller than the smallest known bacteria, and about the same size as a virus. Because viruses need a host to reproduce, this one-in-a-billion creature would set a new record for the smallest living thing on Earth. Scientists pointed out that the fuzz of this extremely small creature is very similar to mold and regenerates very quickly. The results of repeated laboratory analyzes have confirmed that they contain DNA that determines life and genetic genes. The discovery of the world's smallest creatures so deep in the ocean has led scientists to suspect that there may be an unknown world of microorganisms hiding deep below the surface, which may outnumber all living things on the surface.