Bats are able to carry viruses without getting sick because their immune systems have evolved to tolerate them. Bats have higher body temperatures than other mammals, which helps to inhibit the replication of viruses. In addition, bats produce more antibodies than other mammals, which helps to fight off infections. Finally, bats have a higher rate of cell turnover than other mammals, which means that infected cells are more quickly replaced with new, healthy cells.

These adaptations allow bats to carry viruses without getting sick, and they also make them important reservoirs for viruses. Bats are thought to be the natural reservoirs for a number of viruses that can cause disease in humans, including rabies, Ebola, and Marburg virus. However, it is important to note that bats do not always transmit viruses to humans. In fact, most bats do not carry viruses that can cause disease in humans.