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 most dangerous laser classification, Class 4, begins at 500 mW (1/2 watt) for visible light. Class 4 lasers can cause instant eye damage, skin burns, and can be a fire hazard for certain materials. The new devices are four times the minimum for a Class 4 laser. A 2000 mW laser is an eye hazard up to about 1,000 feet away from the laser.