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.
However, like many devices, if misused, it is still a laser and can cause damage. If any single laser beam is over 500 milliwatts, the device is a class 4 product but many of the most popular models have multiple beams. This allow for some class 3 lasers to have a combined power that is higher than a class 4.