dragonfly: slender-bodied non-stinging insect having iridescent wings that are outspread at rest; adults and nymphs feed on mosquitoes etc.
invertebrate: any animal lacking a backbone or notochord; the term is not used as a scientific classification
hyaluronidase: an enzyme (trade name Hyazyme) that splits hyaluronic acid and so lowers its viscosity and increases the permeability of connective tissue and the absorption of fluids