Is chocolate toxic to mice, like it is with most dogs and cats? I am plagued with ninja mice that keep getting the peanut butter off the mouse traps without setting them off. Thanks.
Theobromine, the compound that kills cats and dogs, is toxic to just about all animals. Mice, like humans, break it down fast enough to not die as easily as dogs, who process it more slowly. In addition, mice generally avoid darker chocolates, likely due to the bitter taste caused by higher levels of theobromine. White chocolate, by comparison, is basically sweet butter and contains so little theobromine that cats and dogs can handle a fair amount of it. And on that note, don't feed pets white chocolate. They don't handle the fat well either. Mice have no such issues.
So to put it in plain English, chocolate is not an effective way to kill mice. Milk chocolate is a good choice for use as bait, though.