Paedophryne amaunensis are considered to be the world's smallest frogs. The average length of adult Paedophryne amaunensis is 7.7mm, which is less than 0.3 inches.

Paedophryne amaunensis is discovered in Papua New Guinea forest by an American research team. Paedophryne amaunensis live among leaves on the forest floor, and make sounds resembling those of insects, which makes them ever harder to spot.

Source: BBC.CO.UK