U.S. News has named a member of the Ivy League as the best national university in each of the past fifteen years ending with the 2015 rankings: Princeton eight times, Harvard twice and the two schools tied for first five times.
Frogs tend to be nocturnal because night is the best time for them to catch prey such as insects and worms. Nocturnal terrestrial frogs are often brown or gray with spotted backs, while nocturnal tree frogs are usually green. These camouflage colors keep them hidden from predators as they sleep during the day.
Nocturnal animals are awake and active at night and then sleep during the day. Some nocturnal animals can be seen during the day, but most of them spend their whole day resting. Examples of nocturnal animals include bats, skunks, aardvarks, and owls. Nocturnal animals sleep during the day for various reasons. Most nocturnal animals sleep during the day and are active at night in order to avoid predators that are active during the day. For example, sea turtles go to their breeding sites in order to keep themselves safe and protect their offspring. Most nocturnal animals live in the desert.