The innocent rat

For as long as Mankind had grown grain, he has had to store it. After all, harvest is only once a year.

And for as long as Mankind has had grain stores, he has battled with rats.

They get into grain stores - even the most modern and fortress-like - and gorge on the grain. They leave droppings and urine that is toxic; grain store workers have to watch out for Weil's disease.  In my youth, after a long winter working in our store, I went to the doctor with what I thought was a severe flu: sneezing, headaches, red and painful eyeballs. He gave me the facts about Weil's, then the mother of all bollockings for not arriving in his surgery earlier, and then some industrial antibiotics. Luckily, not being an organic farmer, I took them, and got better.

So we have to control (i.e., kill) the humble rat. UK ACCS legislation means we have to have a complete plan in place.

But how? Poison is the most common way. Bait is left down, the rats eat it, and die. Normally slowly. If it's a warfarin-based poison, they bleed to death after any small cut. (Warfarin is an anticoagulant). We have lost many farm cats the same way, after they caught and ate affected rats.

There's trapping. Large versions of the humble mouse trap, can be effective and quick - but rats are so suspicious, they are hard to tempt into the neckbreaking loop. They're easier to persuade into a funnel trap, which has a one way entrance, but they have to be then disposed of. The classic technique is to drop the whole cage into a water trough, and drown the rat. That can take many minutes.

Then there's gassing. Most of the entrance holes are blocked, and toxic gas (back when we did it on the farm, it was Cymag, Phostoxin or even exhaust from an engine) is introduced to the remaining hole, which is then sealed. It's hard not to feel sympathy for the rat when you hear it screaming below a sealed up exit hole.

If you have a few terriers, there's 'organic' pest control: dig them out and let the dogs loose. It's brutal but quick. There's usually lots of blood, but very few survivors.

Meanwhile, the wheat that's in the grain store goes off to make bread, which is marked 'suitable for vegetarians'.