how do they evolve?
They've evolved gradually, both their defense mechanisms against predators as well as complex groups of coevolved species like pollination, which is beneficial to both organisms.
Insect
nsects were among the earliest terrestrial herbivores and acted as major selection agents on plants. Plants evolved chemical defenses against this herbivory and the insects, in turn, evolved mechanisms to deal with plant toxins. Many insects make use of these toxins to protect themselves from their predators. Such insects often advertise their toxicity using warning colors. This successful evolutionary pattern has also been used by mimics. Over time, this has led to complex groups of coevolved species. Conversely, some interactions between plants and insects, like pollination, are beneficial to both organisms. 
where can you find noisy miner? Eastern and southeastern Australia. how do they behave socially? They are a gregarious species that move and roost in colonies. what do they feed on? Nectar, fruit and insects. what is the scientific name of the last one? Insecta.
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Insect [SEP] Evolutionary relationships
Insects are prey for a variety of organisms, including terrestrial vertebrates. The earliest vertebrates on land existed 400 million years ago and were large amphibious piscivores. Through gradual evolutionary change, insectivory was the next diet type to evolve. Insects were among the earliest terrestrial herbivores and acted as major selection agents on plants. Plants evolved chemical defenses against this herbivory and the insects, in turn, evolved mechanisms to deal with plant toxins. Many insects make use of these toxins to protect themselves from their predators. Such insects often advertise their toxicity using warning colors. This successful evolutionary pattern has also been used by mimics.