Lygaeus kalmii Stal (Hemiptera: Lygaeidae) is an insect found throughout the eastern United States and Canada. There is extensive taxonomic literature on this insect (Stil, 1874; Townsend, 1887; Parshey, 1919, 1923; Slater and Knopf, 1969), but very little attention has been given to the rest of its biology. This study describes the habits of kalmii populations in southern Michigan