One of the basic steps of the external biosecurity in the farm is related to disease entry control by rodents and other vectors such as birds and insects. The diseases for which rodents act as a vector include salmonellosis, bordetellosis, leptospirosis, pseudorabies, porcine dysentery, erysipelas, and toxoplasmosis. These animals are capable of spreading these diseases long distances via feces, skin, urine, saliva and blood. An effective rodent control plan is essential to the farm but the presence of external barriers that prevents the arrival and entrance of these animals into the facilities will increase its success.