Sleep with one eye open

Name me a nocturnal creature.

Owls? Bats? 

Some owls are nocturnal but not all of them. Moreover, their waking hours match that of their prey. Rodents and other small mammals are usually nocturnal. But if their prey are diurnal like birds, they will hunt in the day. 

 

The truth is that nocturnal creatures play to their advantage. Predators in the day? Bats prefer to go night crawling. Your prey prefers night instead of day? Make them pay for watching out for the cold blooded predators. Reptiles do less hunting at night. There are still nocturnal reptiles but if it were not for the mammals, the list of night hunters (or night foragers) will be very short. 

The advantages of being cold blooded? You eat less. Crocodiles can go for half a year without eating.