By finding artifacts
One of the keys of civilization is writing. Some historians look at the time before writing as prehistory, and at peoples with organized cultures but without written language as prehistoric civilizations. There were groups of individuals who worked together and formed human networks among other groups all without the benefit of written language. One of the most famous groups of folks are the native Australians, who lived the way they did for something approaching 40,000 years without scrolls or tablets or any written language. A link to the Wikipedia article on prehistory is provided.
5,500 years ago
Both resemble things or events from the past.
They contain the pictographs of early man and the evidence of early man.
The origin of man has been traced back to Africa 25,000 years ago. I suggest you learn the history of man and how historians have found remains that date to 25,000 years ago.
Prehistory is that very long period of human existence where no written historical accounts were made.
Any written document, otherwise that would be an source and be a part of history.
The word "prehistory" implies "before writing existed". There are no "written sources" from that time.
they think about clues they got when they find artifact's from prehistory that how historians investigate the past.
Historians learn about the past by using artifacts geography written records/books and interviews/oral tradition.
There are a number of things that scientists study to learn about prehistory. This will include archaeological facts and fossil evidence which gives an explanation of how most things came into being.
Bias can be useful to historians by allowing them to learn about people's opinions and beliefs.
Scientists learn about prehistory through a variety of methods, including studying archaeological artifacts, geological evidence, and biological remains such as fossils. By analyzing these materials and using techniques such as carbon dating and DNA analysis, researchers can piece together the story of human and Earth's past. Collaboration among experts in different fields, such as archaeology, anthropology, and genetics, also contributes to our understanding of prehistory.
Because oetzi is the worlds oldest mummy and was found in one of the most interesting stories today
Scientists that learn about the past are called historians because they learn about history/past.
Artifacts, includeing the Torah
Because historians want to know what happened so they can learn all about it :)