Just in the last 3 months I have replaced several motors and timers because ants have infested the electrical equipment. That’s right: ants. Apparently these ants like the sub-audio frequency of electrical equipment. They seem especially fond of committing suicide by climbing in between the contacts of the “old school” yellow dial Intermatic manual clock timers. When they do that, there little bodies form imperfect conductors, and the resultant electrical shorting can burn out the pool pump motors as well as the ruin the timers.