When a leak developed underground in one of his water lines, Mark Himes, Beecher City, Ill., had a frustrating time trying to find the leak.

Finally, out of desperation, he came up with an idea that worked so well he wants to share it with others.

What he did was to tape a styrofoam cup upside down to the top of a 5-ft. long piece of 2-in. dia. pvc pipe. Then he taped a doctor's stethoscope to the bottom of the cup.

"It's unbelievable how well it works to detect leaks. I can hear water coming out of a small leak from about 50 ft. away. As I move closer to it, it sounds like a waterfall," says Himes.

He found his problem leak &endash; which was 4 ft. under ground &endash; by following the waterline out from the pump. The leak turned out to be a crack in the pressure line brought on by uneven settling of ground. "Finding the leak saved me from having to dig up the entire pipe," says Himes.

Before coming up with his homemade leak detector, Himes checked out commercial models and discovered they are available but sell for a lot of money. He doubts any commercial unit works better than the one he put together.

"It's best to use it on a calm day because it's so sensitive it'll pick up wind noise," he notes.

Himes thinks you could use his detector to track moles and other underground pest animals, although he hasn't tried it. You could use the detector to find where they're digging and then stab them by poking through the ground with a pitch fork or other sharp object.