<P> Male grasshoppers spend much of the day stridulating, singing more actively under optimal conditions and being more subdued when conditions are adverse; females also stridulate, but their efforts are insignificant when compared to the males . Late - stage male nymphs can sometimes be seen making stridulatory movements, although they lack the equipment to make sounds, demonstrating the importance of this behavioural trait . The songs are a means of communication; the male stridulation seems to express reproductive maturity, the desire for social cohesion and individual well - being . Social cohesion becomes necessary among grasshoppers because of their ability to jump or fly large distances, and the song can serve to limit dispersal and guide others to favourable habitat . The generalised song can vary in phraseology and intensity, and is modified in the presence of a rival male, and changes again to a courtship song when a female is nearby . In male grasshoppers of the family Pneumoridae, the enlarged abdomen amplifies stridulation . </P> <P> In most grasshopper species, conflicts between males over females rarely escalate beyond ritualistic displays . Some exceptions include the chameleon grasshopper (Kosciuscola tristis), where males may fight on top of ovipositing females; engaging in leg grappling, biting, kicking and mounting . </P> <P> The newly emerged female grasshopper has a preoviposition period of a week or two while she increases in weight and her eggs mature . After mating, the female of most species digs a hole with her ovipositor and lays a batch of eggs in a pod in the ground near food plants, generally in the summer . After laying the eggs, she covers the hole with soil and litter . Some, like the semi-aquatic Cornops aquaticum, deposit the pod directly into plant tissue . The eggs in the pod are glued together with a froth in some species . After a few weeks of development, the eggs of most species in temperate climates go into diapause, and pass the winter in this state . Diapause is broken by a sufficiently low ground temperature, with development resuming as soon as the ground warms above a certain threshold temperature . The embryos in a pod generally all hatch out within a few minutes of each other . They soon shed their membranes and their exoskeletons harden . These first instar nymphs can then jump away from predators . </P> <P> Grasshoppers undergo incomplete metamorphosis: they repeatedly moult (undergo ecdysis), each instar becoming larger and more like an adult, with the wing - buds increasing in size at each stage . The number of instars varies between species but is often six . After the final moult, the wings are inflated and become fully functional . The migratory grasshopper, Melanoplus sanguinipes, spends about 25 to 30 days as a nymph, depending on sex and temperature, and lives for about 51 days as an adult . </P>

How grasshopper adapt to escape from their enemies