We are currently experiencing Norwegian Roof Rat issues in our garage - but the bait content has changed and isn't near as effective; info about d-Con per Wikipedia: https://en.wikipedia.org/wiki/D-CON
: "In June 2014, Reckitt Benckiser and the EPA came to an agreement to end legal action. RB agreed to stop manufacturing twelve products with loose pellets or powder by the end of 2014, with distribution to retailers ending no later than March 31, 2015. Retailers could continue to sell existing stock indefinitely. Eight of the twelve products contained second-generation anticoagulants (brodifacoum or difethialone), which the company agreed not to use in its replacement products." Ingredients
: "Prior to 2015, d-CON primarily used two active ingredients in the bait products. In the rat bait pellets, mouse bait pellets, place packs, and wedge baits, the active ingredient was brodifacoum, typically at 0.005% concentration. In contrast, earlier d-CON products that used warfarin had 0.5% concentration. In the refillable and disposable bait stations, the active ingredient was (and still is) diphacinone. The use of brodifacoum was discontinued at the end of 2014 following an agreement with the EPA, and was replaced with less potent first-generation vitamin K anticoagulants such as diphacinone."