A thesis is typically written by students finishing up a bachelor’s or Master’s degree. Some educational institutions, particularly in the liberal arts, have mandatory theses, but they are often not mandatory to graduate from bachelor’s degrees. It is more common for a thesis to be a graduation requirement from a Master’s degree.
Even if not mandatory, you may want to consider writing a thesis if you:
Plan to attend graduate school soon
Have a particular topic you’d like to study more in-depth
Are considering a career in research
Would like a capstone experience to tie up your academic experience