Dolph Lundgren uses an unusual animal to guard his valuable items. He maintains a collection of 100,000 fleas that he releases into his personal vault. When he wants to get into the vault he opens small doors with blood containers behind them to lure the fleas out of the way. He considered infecting the fleas with some disease, but found that he would fall afoul of Homeland Security regulations if he did. As it is he has to register his home as a biohazard facility. And he has to maintain a constant blood supply to feed the fleas.