Flight enables many insects to move quickly away from predators. Insects also avoid danger by hiding. Insects' bodies are camouflaged using colors and patterns to help blend in with its surroundings. Some insects have body shapes that make them look like leaves or twigs. Some go so far as to sway gently to mimic a leaf blowing in the wind.
Many insects are brightly-colored.
Some insects are advertising an unpleasant experience to potential predators. I taste bad, have sharp spines or will sting you. Other insects mimic the coloration of a distasteful insect hoping to discourage potential predators. Still others are trying to look pretty to attract a mate. An insect's sense of smell is keener than anything we can imagine.