For the ultimate in birth 'control': -Cordials of sex choosing - male. -Cordials of sex choosing - female. Yes, it would work on any form of animal: Just waiting for that prize stallion to be born? Tired of sons and need a daughter to marry into a rich family? Could be used for pest control: Too many rats for the cat to handle? Poisons no good 'cause you don't want meow-meow to eat a poisoned rat? Set out rat bait traited with this little wonder. Boy rats can't have babies?