aposematic coloration

Ladybirds' red colouration with black spots is a warning to potential predators, such as birds, that they are unpleasant to eat. When attacked by ants, ladybirds secrete a sticky fluid that entangles their antennae long enough to allow the beetle to escape. Ladybirds feed mainly on aphids.

In biology, the technical name for warning coloration markings that make a dangerous, poisonous, or foul-tasting animal particularly conspicuous and recognizable to a predator. Examples include the yellow and black stripes of bees and wasps, and the bright red or yellow colours of many poisonous frogs and snakes. See also mimicry.