Earwigs eat aphids and several other harmful pests as well as hosta leaves. Some gardeners put up with the damage and leave the earwigs in the garden to control other pests. You can control earwigs with traps. Place a piece of crumpled paper under a flowerpot or use a tube of paper or bamboo as a trap.
In optics, refraction is a phenomenon that often occurs when waves travel from a medium with a given refractive index to a medium with another at an oblique angle. At the boundary between the media, the wave's phase velocity is altered, usually causing a change in direction.
Refraction occurs when a wave passes from one medium to another and is bent; that is, the wave deviates from the straight-line path it would have otherwise followed. For example, light passing through a prism is bent when it enters the prism and again when it leaves the prism. The light is therefore refracted.