as drugs and illegal immigrants or drugs and guns at the same time) was verified following the completion of a study that found 16 documented cases of smugglers transporting more than one type of contraband in the same shipment. MCC shipments were frequently associated with Phase II and Phase III smuggling organizations. Use of animals In addition to human couriers, smugglers have been known to transport illicit goods with the use of trained animals. One advantage to smugglers using animals is that unlike human couriers, who might turn state's evidence if caught, an animal courier, if caught with any contraband on them, would be unable to provide any verbal information to the authorities. Dogs One way that smugglers have used animals to transport contraband at times is through the use of dogs. Often smugglers have been known to strap drugs onto the backs of canine and then use such dogs as pack animals to transport the contraband across further distances and/or across borders. Cats Another way smugglers have used to transport contraband on multiple occasions is cats. Usually the cats are used to sneak drugs into prisons, where prison gangs can then sell the drugs to other inmates. Often a smuggler from the outside will attach small amounts of drugs to a cat and then the cat will either be lured inside the prison by inmates with cat treats or the cat might be trained to enter the prison. In addition to drugs, cats have also been used to smuggle other kinds of contraband into prison such as cellphones, tools, batteries and phone chargers. The reason why cats can make good drug couriers is due to the fact that felines are naturally stealthy animals and because the prison guards are often less likely to suspect that contraband might be on a cat. Birds Additionally smugglers have also used homing pigeons to transport contraband by air at times. Carrier pigeons have been used to smuggle drugs into prisons and across borders. Additionally homing pigeons have also been used to transport cellphones and SIM cards into prisons. The reason why pigeons have been useful for smugglers, is that they can fly for long distances and because the birds are usually unlikely to arouse much suspicion from authorities, due to the fact that pigeons are such widespread and commonly witnessed birds, in both rural and urban areas. Livestock Smugglers have also been known