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.
The energy in a light beam travels in a straight line at a fixed speed so long as it is in vacuum (as in space). When traveling through most gases, such as those found in our air, light propagates in the same way as in a vacuum â in a straight line at the speed of light (about 186,000 miles per second).