I was wiring up my control box and watched a spider crawl down the wall, through a hole in top of the metal case, then behind the circuit board.
I know that insects have caused problems with computers. Actually this is where the term "computer bug" first originated. There was a bug crawling around on the circuit boards which was causing a computer to crash again and again. The solution was to put screen over the air vents so insects could not get inside.
So I plan to do the same with my control box. Glue fine mesh screen around the sides/top/bottom. Then it will have ventilation, but keep the bugs out.
Anyone know of any problems with insects crawling around on control unit circuit boards? Perhaps this is the cause of some unexplained false alarms?