Insects comprise about 55% of total biodiversity and approximately 85% of that from animals. Insects have colonized all of the terrestrial and freshwater niches under all climates, from polar to desert regions. The omnipresence of insects in any type of ecological system, from waterway to extremely septic environments, has stimulated scientists to look for new therapeutic agents in this class of arthropods. Among the bioactive peptides/polypeptides that have already been characterized from insects, antimicrobial peptides are fascinating scientists for their potential use as therapeutic agents. However, relatively little data are available on molecules from insects with antiparasitic, antiviral, or antitumoral activities. Most available antiviral and antitumor agents have been derived from plant, microbes, and, to a lesser extent, animal secondary metabolites. To date, no peptide from an animal source has reached the level of commercial use as a pharmaceutical compound for anticancer or antiviral Recent progress in biotechnology and immunology has contributed to the list cytokines and some other regulatory polypeptides of human origin. However, huge varieties of peptides or polypeptides from animal, especially insect, origin remain practically untapped in this area.