Discovered in 2012, the Brookesia micra chameleon is among the smallest reptiles in the world. Here a juvenile perches on the head of a matchstick; adults grow to just over one inch.

Photograph by Joern Köhler, Corbis

This artist's rendering shows tiny planets clustered around a red M-dwarf star called KOI-961. Three new planets found outside our solar system are the smallest exoplanets yet discovered—each of them tinier than Earth.

Photograph courtesy NASA/JPL-Caltech

The miniature device placed on this beetle may make it the world's smallest cyborg. Electrodes implanted in the brain and wing muscles allow scientists to remotely control the insect's flight.

Photograph by David Liittschwager, National Geographic

The face of a Eupelmus vuilleti wasp is revealed in this scanning electron micrograph (SEM) image. The technology uses beams of electrons to trace the surface of objects, resulting in detailed magnification of even tiny insects or particles.

Photograph by Christopher Jackson, National Geographic

Viruses are tiny, smaller even than bacteria, but far more numerous than all other life-forms combined. This illustration shows a flu virus particle.

Photograph by Oleksiy Maksymenko, Getty Images

The hourglass tree frog, native to parts of Central and South America, is just under 1.5 inches when full grown. This species is one of many itty-bitty frogs, the smallest of which is just one-third of an inch long.

Photograph by Joel Sartore, National Geographic

Even the smallest slice of an ecosystem can be teeming with life. The creatures pictured here represent the biodiversity found in just one cubic foot of a coral reef.

Photograph by David Liittschwager, National Geographic

Perched on the tendril of a Passiflora plant, the egg of the Julia heliconian butterfly may be safe from hungry ants. The eggs are no larger than .07 inch.

Photograph by Martin Oeggerli, National Geographic