[HamiltonJay]

What did they ban?

It has been my understanding for years, major cities just use Vitamin K bate to kill rats... It kills rats, but is harmless to humans which is why it is used.

[Paul R.]

Eh? I think Vitamin K is an antidote to anti-coagulant poisons. You may have been thinking of Vitamin D3. More info. here:

http://www.petpoisonhelpline.com/wp-content/uploads/2014/01/VPI-PPH-Rodenticides-webinar-Jun-2014.pdf