Originally Posted by Markxxx
I read that Warfarin isn't used so much any more as mice and rats have gotten used to it so it isn't as effective as it once was.
The active ingredient in things like D-Con is now brodifacoum
, which is also an anticoagulant that works much like warfarin. It also has a much longer elimination half life, so that the rodent can die from repeated sublethal doses, which wouldn't build up if warfarin was still used. This persistance causes some groups to claim that it should be banned on the basis of secondary bird poisonings.