Modern laws about poisons have removed various pesticides from sale for ordinary folks. The result of that is entirely predictable: rats have become largely immune to rat poison available to the general public. If a mixture of poisons were available and used in rotation and sometimes together immunity would not develop, but now that immunity is widespread we have no chemical tools available to kill vermin without breaking the law. I'm not going to break the law.
You may have guessed by now that rats are still taking the poison I put out. The poison is a coating on grains of wheat, so if the poison is not affecting the rats then I am simply feeding them grain.
I need a legal alternative.