Insekts

Insekts are a class of hexapod, invertebrate animals within the phylum Arthropoda. They typically have a body divided into head, thorax, and abdomen, three pairs of legs, one pair of antennae, and usually one or two pairs of wings at some stage of their life. The body is covered by a chitinous exoskeleton, and most insects breathe through a network of tracheae connected to spiracles. Insekts display a high degree of morphological and ecological diversity that has enabled them to inhabit nearly every terrestrial and freshwater habitat, as well as some aerial ecosystems.

Most insect species undergo metamorphosis, a developmental process that replaces juvenile forms with adults. There are two major patterns: incomplete metamorphosis (hemimetabolism), where nymphs resemble small adults and gradually acquire mature features; and complete metamorphosis (holometabolism), where life stages are distinct (egg, larva, pupa, adult).

Taxonomically, insects are divided into numerous orders, with beetles (Coleoptera), butterflies and moths (Lepidoptera), flies (Diptera), bees, wasps and ants (Hymenoptera), true bugs (Hemiptera), and grasshoppers and crickets (Orthoptera) among the most diverse. Some groups lack wings, while others have lost wings secondarily. Insects play critical roles in ecosystems as pollinators, decomposers, predators, and prey.

Humans interact with insects in varied ways. They can be agricultural pests, disease vectors, or beneficial organisms in agriculture and natural ecosystems. Insect populations respond to environmental changes, pesticides, and habitat loss, making conservation of pollinators and other functional groups a topic of interest for biodiversity management.