1 Place the cotton balls in areas where mice are likely to enter your house, by doorways or heat vents, etc. 2  Another helpful deterrent is to grow peppermint plants near the entryways. 3  You can use the mint in cooking as well as it serving a deterrent purpose.
Nov 12, 2015. 20 kilometers (12 miles) for a 1 milliwatt beam. Laser light can travel 20 kilometers (12 miles) per-milliwatt that is contained within the laser.
Spatial coherence also allows a laser beam to stay narrow over great distances (collimation), enabling applications such as laser pointers. Lasers can also have high temporal coherence, which allows them to emit light with a very narrow spectrum, i.e., they can emit a single color of light.