Heh. Langton's Ant was the first program I wrote when I was learning to program in Cobol on a mainframe, circa 2015, while working at <BIG FINANCIAL CORP>. I daresay I read about it in The Science of Discworld, like another commenter. The Cobol ant was not animated, mind- I just wrote out the end result after a sufficient number of iterations to get the characteristic shape, as in the wikipedia image.

I had a look though and I can't seem to find the code. Shame, as I think the square grid had a very natural representation in Cobol that gave me some nice insights about the language.