Wing Scales Help Camouflage From Sonar

varying soft rectangular shapes layer together in bright yellow, orange, and black colors in this hyper macro image of a few scales on the wing of a moth

Biological Strategy

AskNature Team

Image: Robert Vierthaler / Flickr / CC BY - Creative Commons Attribution alone

Send Sound Signals

Many living systems send auditory signals to communicate with others, including to attract, announce, or warn. These sounds must be audible to the intended recipient in a variety of conditions, such as in wind, water, and solids. As a result, each living system has specific sounds best adapted to its environment. For example, some birds live in loud habitats, like those alongside noisy streams or in windy areas. These birds use sound frequencies that can be heard by other birds over competing environmental noises.

Search this Function

Modify Size/Shape/Mass/Volume

Many living systems alter their physical properties, such as size, shape, mass, or volume. These modifications occur in response to the living system’s needs and/or changing environmental conditions. For example, they may do this to move more efficiently, escape predators, recover from damage, or for many other reasons. These modifications require appropriate response rates and levels. Modifying any of these properties requires materials to enable such changes, cues to make the changes, and mechanisms to control them. An example is the porcupine fish, which protects itself from predators by taking sips of water or air to inflate its body and to erect spines embedded in its skin.

Search this Function

Protect From Animals

Animals–organisms that range from microscopic to larger than a bus–embody a wide variety of harms to living systems, including other animals. They threaten through predation, herbivory, defense, and parasitism, and they compete for resources such as water, nutrients, and space. Any given living organism commonly faces threats from a variety of animals, requiring strategies that effectively defend from each. Trout and other bony fish, for example, escape predators by having scales made of very thin, flake-like pieces of bone covered with slippery mucus. They also have behavioral strategies such as camouflage, fast swimming, and twisting and turning to achieve release from a predator’s grip.

Search this Function

Insects

Class Insecta (“an insect”): Flies, ants, beetles, cockroaches, fleas, dragonflies

Insects are the most abundant arthropods—they make up 90% of the animals in the phylum. They’re found everywhere on earth except the deep ocean, and scientists estimate there are millions of insects not yet described. Most live on land, but many live in freshwater or saltwater marshes for part of their life cycles. Insects have three distinct body sections: a head, which has specialized mouthparts, a thorax, which has jointed legs, and an abdomen. They have well-developed nervous and sensory systems, and are the only invertebrate that can fly, thanks to their lightweight exoskeletons and small size.

Search this Living System

The scales on moth wings help camouflage them from predatory bats because their uneven shape prevents the bats' sonar from detecting them clearly.

Image: Ro Irving /

Image: Janice Carr (photo credit) and Oren Mayer(content provider) / Centers for Disease Control and Prevention /

Under this relatively highly magnified scanning electron micrographic (SEM) view, some of the wondrous ultrastructural shapes found on the surface of an unidentified white moth were revealed. This moth, discovered deceased in the Decatur, Georgia suburbs, was a member of the Phylum Arthropoda, Order Lepidoptera. At this level of magnification, 1388X, the proximal strut of one single scale could be seen as it inserted into its exoskeletal pore, while another scale was entirely extracted from its insertion site. Imagery such as this brings to life, the incredible microscopic beauty, which goes unseen, but is abundant all around us.

Image: Janice Carr (photo credit) and Oren Mayer (content provider) / Centers for Disease Control and Prevention /

“The moth’s first defense again comes from those fuzzy scales it has all over its body. To us they just seem ungainly, a mistake. But because of their uneven shape, they give the bat only a fuzzy outline on its sonar scope.” (Bodanis 1992:169)