One of the structures on our farm has a rat problem. They're chewing through the plumbing and the results have been disastrous.
The exterminator we hired examined the site and let us know it would be cheaper to solve the problem ourselves, as it requires distributing rat poison in the crawlspaces every week, until all of the rats are dead. I asked him how we would know that we got them all, and he shared this interesting piece of information:
All rat poison is required by the EPA to be dyed in bright, vibrant colors. This is ostensibly for human safety; if a child shows up at the ER with a bright green tongue, the doctors know what to do.
The bright coloring, however, also helps exterminators. As you crawl around under a house inhabited by rats, you'll spot rat droppings, which are naturally dark. But when they eat the poison, their poop turns green (or whatever color the poison is dyed).
Each week as you get under the house, he said, examine all the droppings. When you stop seeing any dark droppings and only see bright green droppings, you'll know you got 'em all. Until then, keep distributing the poison.
Eventually comes the fun part: Finding and disposing of the rotting corpses. #countrylife