Anyone heard of a dying agent that can be added to gasoline (like they do in off-road diesel). We've got someone siphoning fuel out of two of the mowers that stay on an open trailer some nights. This has happened twice now since the season started and is more of an annoyance than a real threat but I'm ready to hurt someone over it. I think it's one of the neighbors at our mowing lot. They take 2-3 gallons (maybe a little more) out of each machine and leave the 5 gallon blitz can untouched---maybe thinking I won't notice. Other option is to mix in some bleach in the one machine and leave it on there as a booby trap.