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.
A red laser pointer of the semiconductor or diode variety that you can buy as a toy may be able to put a dot onto an object at night around 1,500 meters away. If you use it in a very heavy fog, you will see the very thin laser beam coming from the laser. In a simple laser, a flash puts light into a rod or other component, where the atoms become excited, and some of the atoms within it emit photons, which bounce back and forth between a set of mirrors.