Diphenadione inhibits the clotting of blood; that is, it is an anticoagulant. It is used to control vampire bat populations in South America by a “Trojan horse” strategy. A few bats are trapped, smeared with Diphenadione, and then released back into their normal environment. Other bats, in the course of grooming these diphenadione-coated bats, ingest the anticoagulant and bleed to death, either internally or through accidental bites and scratches.