A "robber frog" whose body is just 10 millimetres (three-eighths of an inch) long eats toxic mites and exudes their poison on its skin to deter predators, scientists reported on Wednesday.
The tiny creature is called the Monte Iberia eleuth -- Eleutherodactylus iberia -- after a mountain in Cuba which is its only known habitat.
Just five other species of frog, including the amphibian's Cuban cousin, Eleutherodactylus orientalis, share the unusual ability to take toxic alkaloids from their diet and sequester the compound on their skin.
The Monte Iberia eleuth is the smallest frog in the northern hemisphere.
It is also the second smallest in the world after the Brazilian gold frog (Psyllophryne didactyla), which measures just 9.8 mm in body length.
The Monte Iberia eleuth is part of a family of amphibians called robber frogs, of which there are several hundred in the Caribbean and the southwestern United States.
The origin of the name is unclear.
The study appears in Biology Letters, published by Britain's Royal Society.
Explore further: Three things you didn't know about the arachnids that live on your face