The farmers peas

There was a farmer in Cheshire who had several fields of peas.His biggest problem was the local kids who would constantly pinch some over night.
After losing many peas and giving it much thought he came up with a brilliant idea.This would scare the kids off for good. He made up some signs and planted
them in the fields.
The next day the kids showed up and read the signs: "Warning..one of these peas has been injected with cyanide."
So the kids ran off and came up with an idea of their own, made some signs and posted them next to the farmers signs.
A few nights later the farmer inspected his peas and they were all intact, none were missing. Then he noticed the new signs which read:
"Now there are two."