Bombus frigidus, the frigid bumblebee, is a rare species of bumblebee largely found in Canada and parts of the United States. These bees have adapted to their cold environment by being able to keep their internal temperature within a certain range while also being able to expel heat to keep the colony warm. An additional adaptation to the cold is their reduced length of copulation. Also, B. frigidus has developed a relationship with Mertensia paniculata so that the flowers' color signals to the bees when to obtain nectar.