What do you call animals that are active during the day?

Animals that are active during the day are referred to as "diurnal." This term specifically describes the behavior of species that primarily operate in daylight hours, which is an adaptation that allows them to take advantage of sunlight for foraging, hunting, or social interactions. Diurnal animals often have physiological traits suited for daytime activity, such as good color vision, which helps in locating food and navigating their environments.

In contrast, "nocturnal" refers to animals that are active at night, which may have adaptations for low-light conditions. The terms "carnivorous" and "herbivorous" pertain to diet rather than activity patterns; carnivorous animals primarily eat meat, while herbivorous animals primarily consume plants. Hence, the term "diurnal" is the appropriate descriptor for animals that are active during the day.