Why lady birds are brightly coloured?

Answer 1

If you are asking about birds, with only a few exceptions, it is the males who are much brighter in color than the females (or the lady birds). For example, the male cardinal has a bright red body, while the female only has a reddish-orange beak and her body is all brown. Similarly, male blue jays are a much brighter blue color than females, and the same is true with male grackles (they are black and shiny, with purplish heads, while the females tend to be greyish-brown); and even male peacocks are brighter and more beautiful than the female is. A few species, such as certain kinds of parrots, have brightly colored females, and the female sandpiper is much more distinctive than the male. But in general, the males are brighter and more colorful in most of the species of birds.

But if you are asking about what we call the "ladybug" and some people call the ladybird, these are a kind of beetle whose bright colors and spots are meant to warn off predators; ladybugs do not taste good, and predators know when they see these insects, they should leave them alone. In nature, ladybugs are useful because they eat smaller insects (aphids) and prevent them from killing plants.