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.
Look up nocturnal in Wiktionary, the free dictionary. Owls are well known for being nocturnal, but some owls are active during the day. Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is nocturnal, versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed senses of hearing, smell, and specially adapted eyesight. Such traits can help animals such as the Helicoverpa zea moths avoid predators. Some animals, such as cats and ferrets, have eyes that can adapt to both lowlevel and bright day levels of illumination. Othe