This creature 's eating habits can be modeled with a Markov chain since its choice depends on what it ate yesterday , not additionally on what it ate 2 or 3 ( or 4 , etc. . . ) This creature 's eating habits can be modeled with a Markov chain since its choice depends on what it ate yesterday , not additionally on what it ate 2 or 3 ( or 4 , etc. ) days ago .