books.google.com - Behavioral thermoregulation by ectotherms through selective timing of activity and habitat use involves costs, as well as the benefit of improved physiological function from maintaining optimal body temperatures. Under the cost-benefit model, reptiles should thermoregulate carefully only when the benefits...https://books.google.com/books/about/Habitat_Use_and_Thermal_Ecology_of_Ratsn.html?id=ZureYO7nCrYC&utm_source=gb-gplus-shareHabitat Use and Thermal Ecology of Ratsnakes (Elaphe Obsoleta) and Racers (Coluber Constrictor) in Illinois