I am 70 now, spent my last 50 years as a electronic's engineer. The main problem with any build is cost and will it work. this kit fixes both problems, the PCB is built, so it works, and it's good value. last winter I had mice in with my classic motor bikes. luckily they did not destroy anything of value, but they do need to go. So I purchased 8 ultrasonic pest controllers and the bat detector was very useful to listen to them working, so far no spiders or mice.